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BIO Chemistry EXAM I
Question | Answer |
---|---|
Facilitated diffusion is the movement of molecules or ions from high concentration to low concentration through a protein channel | allow ions (Na+, K+), small polar molecules and large biochemical molecules to pass through aided by a protein flow with a concentration gradient no energy required [High] to [Low] |
Active transport | transport against the concentration gradient require energy ATP, conjugate gradient, electrochemical |
uniporter | |
sympoter | |
antiporter | the sodium-potassium pump in type of co-transporter( a transporter that moves more than one solute at at time) |
membrane: peripheral protein integral membrane protein | alcohol go toward the phosphate group (OH have 2C), high concentration basically dissolve the membrane that's why the dye leaking out - MORE ABSORBANCE Propanol is the most damage with the phospholipid , the longer the better be able to interact with h |
cis-unsaturated fatty acid as the substituents | C=C bound on the same side |
2 factors consider with melting point | saturation- more unsaturation decrease melting point number of Cs- smaller chain decrease melting point CH3(CH2)18COOH- total 20Cs, mp will up |
the RXNs between an unsaturated acid and H2 in the presence of metal catalyst (hydrolysis RXNs of a wax) go from an alkene to alkane (saturated to unsaturated) | Hydrogenation (Pt/Pd) |
general structure of glycerophospholypid is a single polar amino alcohol group attached to a phosphate group, and two non-polar tails that are fatty acids | One polar head with two non-polar tails |
amino acids: building block of protein | contain at least 1 Carboxyl group and 1 amino group 20 amino acids found in peptides and protein are ~a-amino acids |
~a-amino acids are chiral | alway has 4 substituents and is tetrahedral |
All (except proline) have | an acidic carboxyl group a basic amino group an ~a hydrogen connected to the ~a carbonyl |
Looking down the H-C bond, toward the ~a carbon clock wise u get | CORN |
amino acids | All are hydrophilic and capable of hydrogen bonding classified depend on their side chain: 1. Nonpolar (Alanine (Ala), Glycine (Gly), Leucine (Leu), Isoleucine (ile), Methionine (Met), Phenylalanine (Phe), Valine (Val), Tryptophan (Trp), Proline (Pro) |
Alcohol, Amine uncharge | 2. Polar-neutral side chain: Asparine (Asn)-amide group, Cysteine (Cys)-thiol group , Glutamine (Gln), Serine (Ser), Threonine (Thr), Tyrosine (Tyr)-phenol |
carboxylic acid, 1 C chain in backbone | 3. Acidic side chain: Aspartic acid (Asp), glutamic acid (Glu) glutamate |
amine group side chain have extra amine [NH2] group | 4. Basic side chain: Arginine (Arg), Lysine (Lys), Histidine (His) <Ph7 |
1. Non-polar sidechains: Alanin (Ala), Glycine (Gly), Leucine (Leu), Isoleucine (ILe), Methionine (Met), Phenylalanine (Phe), Valine (Val), Tryptophan (Trp)- non polar, not soluble cause it had ring, Proline (Pro) | |
Types of Lipid | 1. Energy-storage: triacylglycerols 2. Membrane lipid: phospholipids, sphingoglycolipids, cholesterol 3. Emulsification lipids: bile acids 4. Messenger lipids: steroid hormones and Eicosanoids 5. Protective-coating lipid: biological waxes |
Fatty Acid building block for other lipids Deprotonated carboxylic acids (COO-) Saturated(all single bonds) have higher melting point than unsaturated (cis conformation) Amphipathic | Carboxylic acids between 12 to 20 C even number of C (amphipathic), (polar head) Saturated Fatty Acids Monounsaturated Polyunsaturated |
Saturated Fatty Acids contain only single bond have higher melting point and boiling points | Stearic acid Hydrocarbon tails can closely pack together , increase hydroC chain length increased London forced, with increasing hydrocarbon chain length As number of carbons increases, so does boiling point |
Monounsaturated Fatty Acids contain one double bond | Oleic acid (cis) |
Polyunsaturated Fatty Acids contain TWO or MORE double bond | Linoleic acid |
Unsaturated fatty acids with cis- double bonds cannot pack as tightly | lowers amount of intermolecular forces leads to decreased melting and boiling points |
Carboxylic acids are soluble in water Aectic acid , Hexanoic acid, Myristic acid (a fatty acid) | Fatty acids contain a carboxylic acid the hydrocarbon chain makes fatty acids insoluble |
Forming the conjugate base of a carboxylic acid increases the solubility in water | Benzoic acid (low water soluble)>Sodium benzoate (water soluble) |
Reacting fatty acids with NaOH forms the anion increasing the hydrophilic nature | Become ampiphathic (have hydrophilic and hydrophobic end) Stearic acid (hydrophobic)>Sodium stearate (amphipathic) |
pKa of carboxylic acids is around 5 Stearic acids (hydrophobic)>Sodium stearate (amphipathic) | Rmb if pH>pKa then [A-]>[HA] the carboxylate ion predominates in the human body |
Omega-3 Fatty Acid | letter omega last C on the hydrocarbon chain is designated omega numbering starts with omega carbon Linolenic acid: the first double bond is on C 3 |
Omega-3 Fatty Acids essential nutrient | consumed in diet because it can't produced by the body Found in some plant oils (flax, canola) and cold water fish (salmon, herring) |
Benefit of Omega-Fatty Acids - good cholesterol | increased HDL levels lowered LDL and triglyceride levels decreased blood pressure lower risk of heart disease decreased inflammation of rheumatoid arthritis |
NON ESSENTIAL FATTY ACIDS | Stearic acid, oleic acid, palmitic acid |
FATS & OILS TRIGLYCERIDES- Non polar | made from three fatty acids and glycerol (BY ESTERIFICATION) Glycerol is a triol CH2(OH)-CH(OH)-CH2(OH): polar |
FATS | contain more saturated fatty acids have melting points above room temp Solid |
Vegetable oils | high percentage of unsaturated fatty acids have melting point below room temp Liquid |
TRIGLYCERIDE these are the end product of digesting and breaking down fats in meals | Primary role is provide energy Gram-per-gram basis, triglyceride provide twice as many calories as carbohydrates and proteins Stored in adipose tissue (fat cells) in humans as stored energy |
#O3 important RXNs of Triglyceride | 1. Catalytic hydrogenation (alkene + H2/Pt~ alkane) 2. Oxidation (alkene + 02~ aldehyde or carboxylic acid) 3. Saponification (Ester hydrolysis in presence of OH-) |
Catalytic hydrogenation (REDUCTION) | alkenes react with H2 and platinum (Pt) to produce saturated alkanes |
Partial hydrogenation is used to make vegetable oil | Partial hydrogenation of unsaturated vegetable oil converts some double bond from cis to trans |
AUTOOXIDATION | alkenes react with O2 present in air Small organic molecules produced (have unpleasant odors) Triglyceride has spoiled (gone rancid) Reducing number of alkenes and keeping product cold slows autooxidation |
SAPONIFICATION a RXNs carried out in an alkaline (basic) solution a hydrolysis RXNs that occur in basic solution | a. Methyl acetate (CH3CH2COOCH3) +NaOH ~ Sodium acetate (carboxylate ion ) + HOCH3 b. prods: Sodium laurate, Sodium oleate, Sodium stearate + Glycerol (ESTER HYDROLYSIS) |
STEROIDS #O3 important types 3 fused 6-membered rings and 1 5- membered ring | 1. Cholesterol 2. Steroid hormones 3. bile salts |
Cholesterol component of atherosclerosis | not found in plants manufactured in the liver not fully water soluble, transported through body by lipoproteins |
# different types of LIPOPROTEINS | Chylomicrons mainly carry triglycerides Very low density lipoproteins (VLDLs) Low density lipoproteins (LDLs) High density lipoproteins (HDLs) |
High density lipoproteins (HDLs) | carry phospholipids and cholesterol from cell to the liver > "good" cholesterol |
Low density lipoproteins (LDLs) protein bound to lipids (more fats) | carry cholesterol and phospholipids from the liver to the cells > "bad" cholesterol |
Very low density lipoproteins (VLDLs) | carry triglycerides, phospholipids and cholesterol |
Esterification Glycerol has three alcohol groups, on each C, each of them can form an ester form | the RXNs of an acid (condensation of the carboxyl group of the acid) with an alcohol (the hydroxyl group of the alcohol) in the present of a catalyst |
Fischer Esterification | -OH group of carboxylic acids replaced with -OR group from alcohol. "O" atom of alcohol is the nucleophile |
Hormones | molecule that regulate the funcs of organs and tissues |
Steroid Hormones messenger lipids | synthesized from cholesterol (is the biosynthetic precursor of all steroid hormones) include Sex hormones and adrenocorticoid hormones |
Bile Salts | produced from cholesterol some are released from gallbladder into small intestine - help aid digestion by forming emulsion with lipids |
the Acid Hydrolysis of Ester biomolecule RXNs | converted into alcohol and acid (shift to right) |
Phospholipids #O2 classes make up of a fatty acid, a phosphate and an alcohol | 1. Glycerophospholipids 2. Sphingolipids |
Phosphate | refers to phosphoric acid and three related compounds form present depends on pH can react with an alcohol to form a phosphate ester |
1. Glycerophospholipids consist of residue of glycerol, 2 fatty acids, phosphate, alcohol | effective emulsifying agents because of amphipathic nature Emulsion: colloid formed by combining two liquids Ex: mayonnaise |
2 Sphingolipids consist residue of sphingesine, 1 fatty acid, phosphate, an alcohol | present in myelin sheath around nerve cells |
Glycolipids contain saccharide | contain sugar residues sugars generally attached to sphingosine some sugar residues help determine blood type |
Eicosanoids Nonsteroidal anti-inflammatory drugs (NSAIDs) block the action of an enzyme involved in conversion of arachidonic acid into prostaglandins and thromboxane Ex: Aspirin, ibuprofen Some anti-asthma drugs block the production of leukotrienes | hormones that are derived from arachidonic acid and other essential 20-C fatty acids - "essential" nutrients are ones the body does not produce Ones are responsible for causing pain, inflammation, fever, blood, clotting, muscle contractionsin lungs.lek |
MEMBRANES peripheral protein & integral protein hydrophobic , polar head Cholesterol and protein | incorporate various lipids and other biomolecules Fluid mosaic model selectively permeable small nonpolar molecules can pass through membrane via diffusion |
INTEGRAL protein | embedded in the phospholipid bilayer which can produce substances that can be transported into and out of the cell |
PERIPHERAL protein | loosely bond to membrane surface and easily seperated from it |
Passive processes | Substances move across plasma membranes with out assistance from the cell |
Chylomycrons | a droplet of fat present in the blood or lymph after absorption (triacylglycerols) from the small intestine to liver and to adipose tissue |
Lipoprotein | hard to lower with diet/exercise increase risk for plaque formation more of an inherited/indep. risk factor |
How do nonsteroidal anti-inflammatory drug (NSAIDs) reduce inflammation and elevated temperatures | block the production of |
FATTY ACID ESTERS | type of ester results from the combination of a fatty acid with an alcohol alcohol (glycerol), esters produced can be monoglycerides, diglycerides or triglycerides Dietary fats are triglycerides |
there are two types of proteins in the phospholipid bilayer | Integral membrane protein-penetrates the cell membrane Peripheral membrane protein is a non-penetrating membrane protein located on the surface of the cell membrane |
CELL MEMBRANE | is a lipid-based structure that separated a cell's aqueous based inferior from the aqueous environment surrounding the cell. It's separate CONTROL the movement of substances into and out of the cell |
cell membrane structure | two-layer-thick soluble in water. They're insoluble in water. have one head and two tails. Polar head (hydrophilic) and non-polar (hydrophobic tails) |
#O3 types of membrane lipids usually found in cell membranes | Phospholipids, Glycolipid, and Cholesterol |
LIPID BILAYER | two-layer-thick structure of phospholipids and glycolipids where the non polar tails are in the middle and the polar head are on the outside surface |
Purpose of cholesterol molecules in the cell membrane | regulate membrane rigidity |
Purpose of proteins in the phospholipid bilayer | responsible for moving substances such as nutrients and electrolytes across the membrane |
Normal levels HDL >40 mg/dL LDL <100 mg/dL | Total <200 mg/dL LDL/HDL ratio: <2.5 |
Major function of Lipoproteins | suspend lipids and transport them through the bloodstream |
micelle | spherical cluster of molecules in which the polar positions of the molecules are on the surface and the non polar positions are located in the interior |
Saponification of animal fat is how what is made | SOAP forms a three-dimensional structure called a micelle in which the non polar tails segregate inside (to get away from the water) and the polar head groups go to the outside ( to interact with the water) |
For fats & oils, the products of saponification are | Glycerol and Fatty acid salts |
Inuit people have a diet high in fat, but they have a low heart disease risk in the population. The American diet is high in fat too but they have a high risk of heart disease? | Inuit diet consists of omega-3 fatty acids (from fish)-cold fish, also call fatty fish. Ex: tuna, salmon, and mackerel US diet high in omega-6 fatty acids (from plant oils) |
Emulsification lipids | is lipids suspended in a liquid. We need this in our body for bile acids secreted by the liver emulsifying the fats Help us digest fat soluble vitamins |
SIMPLE DIFFUSION Steroid molecules are non polar fat-soluble molecules would expected to diffuse directly across the phospholipid bilayer.) | which mechanism would a steroid molecule diffusion into the cell? |
GLUCOSE | which of the following NOT diffuse through the plasma membrane by means of simple diffusion? A. Oxygen B a steroid hormone C glucose D a lipid-soluble vitamin |
The difference between integral and peripheral proteins? | Integral proteins are in the lipid bilayer and appear on both side of the lipid bilayer Peripheral proteins are on one side of the membrane (outer or inner) |
Glycerol has three alcohol groups One on each C, and each of them can form an ester bond | what is the maximum number of positions in glycerol that can undergo esterification? |
Alcohol will be glycerol and the carboxylic acid salt will be the salt of a 14-C fatty acid | Saponification refers to the hydrolysis of an ester by a strong base, a RXNs that produces an alcohol and the salt of the carboxylic acid |
Beta-glucans that are partially hydrolyzed during the malting process may be partially soluble. However, when the beer is cold, these oligosaccharides or polysaccharides will start to come out of solution | Sometimes beer can have a "haze" due to insoluble (or partially soluble) substances especially at colder temperatures. This haze is most likely due to? |
branched polysaccharides such as beta-glucans and amylose | long chain carbohydrate polymers are not very soluble in water (or other solvents) |
Glucose and maltose are both water soluble. | Small molecules with many hydroxyl groups are capable of hydrogen bonding with increases solubility |
The structure of amphipathic in Fatty acids | hydrocarbon tail is non polar and the carboxylic head is polar |
D-glucose also called Dextrose or Blood sugar is the most important? | Monosaccharide in human metabolism - D is the only biologically active - D is the only one we can eat released when starch and glycogen are broken down |
Interaction between saturated fatty acid | has strong London forces - High melting points - High boiling points |
Interaction between a Cis double bond in a fatty acid | Has weaker London forces - Lower melting points - Lower boiling points |
Explain why stearic acid has a higher melting point than Laurie acid? | cause a significant bend in the hydrocarbon tail which prevents close packing. Thus, London dispersion forces are decreased. Decreased intermolecular attractions between molecules results in lower melting point |
Condensation Polymers | Polyesters are condensation polymers. They are formed by eliminating a small molecule Ex: H2O when combining - Diacid: 2 carboxylic acids - Diol: 2 alcohol groups in a molecule |
Waxes | Hydrophobic Easter produced by combining fatty acids with long carbon chains |
In Deoxy sugar, deoxy means taking away an -OH | a hydrogen atom replaces one or more of the OH groups in the monosaccharide |
In Amino sugars | an -OH group of a monosaccharide has been replaced by an amino NH2 group |
the carbonyl group of a monosaccharide has been reduce to ? | Reducing a sugar and producing an alcohol on top |
Sugars that can freely interconvert between cyclic structure and the straight chain form with an available aldehyde or ketone .. | Reducing sugar |
It doesn't have a hydroxyl only hydrogen and C | Non-reducing sugar Ex: Sucrose - have both anomeric C atoms in acetal and ketal linkage |
Aldehyde and Ketone groups | AK= reduced |
Aldehyde and Alcohol | AA= oxidized |
the reduction of a C=O group is an aldehyde or ketone produces ? | Alcohol sugars |
Will oxidized only Aldehyde groups to Carboxylic acid - It will go from blue to red orange (complete) - It will indicate the presence of an aldehyde - A sugar that reacts with Benedicts solution is called reducing sugar | Benedict's reagent is a copper compound that |
Carboxylic Acids - Generally ketones CANNOT be oxidized but certain ones such as Fructose can be converted into an aldose undergo [O] to produce a Carboxylic acid | Certain ketones such as fructose can be oxidized by Benedict reagent under basic condition to form what type of compound ? |
a pair of cyclic hemiacetals with the OH on the hemiacetal C in different positions a- Alpha pointing down b- Betta pointing up | Anomers |
a disaccharide with a twist different residues and No hemiacetal | Sucrose table sugar |
a hemiacetal or a dugar residue is connected to an alcohol group of a lipid by glycosidic | Glycolipids |
polar, hydrophilic, basic | Histidine basic amino acid side chain |
contains both a negatively and a positively charge group so its overall charge is neutral pH14 of Valine (one note Acid-Base) | zwitter ion two opposite inter-charge with each other |
Alanine and proline both only have hydrocarbons in their side chain and therefore hydrophobic and non-polar Serine has an alcohol in its side chain and is therefore hydrophilic/polar | Hydrophobic means "fear of water"- non-polar |
Aspartic Acid and Histidine are polar Methionine isa thiother, non-polar | Aspartic Acid has a deprotonated carboxylic group and Histidine has a positively charge imidazole group |
Carboxylic acid is acid and donate proton at pKa Smaller pKa, stronger acid | |
equilibrium constant for an acid pKa= -log Ka | Ka |
Thus there will be a carboxylate anion and an amine group give negative charge to the amino acid | When the pH is greater than the pl, the two group become protonated |
the structure the amino group is not protonated. a-amino groups have K values between 9 and 20, where half are protonated and half are not. The pH must be well above 10 for the complete lack of proton, so only the pH 12 is a possibility | Valine @varying pH - As increase the pH, the amino acid becomes negatively charge - As lower the pH, the a.a become positively charge |
At a high pH all side chains become fully deprotonated The side groups will be COO- and -NH2 Overall the charge will be -1 | Glycine at pH 13, has pl of 5.97 |
pH at which the overall charge of an amino acid is neutral - In acidic solution (H<pl) - COO- accept proton - In basic solution (pH>pl) - NH3+ donates proton | Isoelectric point (pl) pI = COOH + C2NH3 / 2 = (2+9)/2= (5.5-6) most a.a |
Ex: Leucine: pKa(a--COOH): 2.36 pKa(a-NH3+): 9.60 | NET NEUTRAL CHARGE pl = pKa(a--COOH) + pKa(a--NH3+) / 2 |
pl= average of the pKa of the COOH group and the pKa os the COOH group of the side chain (or the two least pKa values) | For Polar Acidic and Basic a.a pl= pKa(a-COOH) + pKa(R-COOH) / 2 |
pl= average of the pKa of the NK3+ group of the backbone and the NH3+ group of the side chain (or the two highest pKa) values | pl= pKa(a- NH3+) + pKa(R- NH3+) / 2 |
Aspartic Acid; pKa(a- COOH): 2.09 pKa(R-COOH): 3.86 | PI= 2.98 |
Lysine pKa(a- NH3+): 8.95 pKa(R- NH3+): 10.79 | PI= 9.87 |
TABLE 12.1 | |
Draw the amino acid glutamic acid at pH of 1.0 and 7.0 The Isoelectric point = 3.2 | |
Polypeptide sequences are written in order starting with the amino end and ending with the carboxyl end, so the C-terminal amino acid is Glutamine | |
Sodium Stearate is more water soluble. Stearic acid is overall non polar because the non polar tail "overwhelms" the polar head group. Sodium stearate is an ionic compound. The ionic part is so polar that it makes the compound amphipathic | which is more water soluble-Stearic acid or sodium stearate ? |
Amide bond joining two amino acids together make an amide | Peptide bond loose rotation of C |
Stearic acid is a carboxylate acid. Sodium stearate has one fewer H+ than Stearic acid.<definition of conjugate base of an acid> | Stearic acid is the acid and sodium stearate is the conjugate base of the acid |
All fatty acids mostly interact via London forces on the hydrocarbon tail The non polar tails line up and the polar head groups line up Natural fats have cis double bonds. | How does unsaturated impact the intermolecular non covalent interactions between molecules of the same fatty acid? |
Because of this, there are "kinks" in the hydrocarbon tails of unsaturated fats which force the non polar tails apart from each other when they interact. | So, the intermolecular forces are weaker for unsaturated fatty acids because the hydrocarbon tails are further apart from each other. |
A saturated fatty acid: lauric acid, myristic acid, palmitic acid, and stearic acid | Linoleic acid has (from left to right): 1 CH3, 4 CH2, 2 CH= CHCH2, 6 CH2 and 1 COOH |
A monounsaturated fatty acid: palmitoleic acid, oleic acid | |
A polyunsaturated fatty acid: linoleic acid, linolenic acid | |
Non polar. Triglyceride 3 very long hydrocarbon chains attached to the three ester groups, the hydrocarbon parts "overwhelm" the polar ester groups | RXNs of 3 fatty acid and 1 backbone is polar or non polar? why? |
When u put soap in water, the non polar tails are repelled by the water because water is highly polar. | How soap behave in H20. If u put a drop of soap in water, what happens? |
Olive oil is a triglyceride so it is non polar . Therefore, Soap would form the opposite structure The non polar tails are attached to the non polar olive oil, while the polar head groups are repelled by the polar olive oil. | How soap behave in olive oil? |
So, an "inside out " micelle in which the polar head groups segregate inside to get away from the non polar tails go out to interact with the non polar oil | A second response is the soap may form a monolayer on top of the oil. The non polar tails would stick into the oil because they are both non polar and the polar head groups would stick outside because they're repelled from the oil |
are molecules that are comprised of the same number and types of atoms (identical molecular formulas) with the same bond connections, but differ in their 3-dimensional arrangement of atoms | Stereoisomerism |
two molecules that are non-super imposable mirror images of each other | Enantiomers |
C center that have 4 single bonds to 4 different atoms of atoms attached | Chiral C |
C1 has #03 different groups attached. The double bond to oxygen is considered two bonds to oxygen C2 has #04 groups (-H,-OH,-CH2OH, and CHO)0 C3 has #04 groups attached (-OH,-H,-H, and -CHOHCHO) | Glyceraldehyde |
on the LEFT | N-terminus (end with unreacted amino group) |
on the RIGHT | C-terminus (end with carboxyl group) |
H3N+(CHCH2OH)CONHCH(CH2COOH)CONHCOO- | Ser(CH2OH)- Gly(H)- Asp(CH2COOH) @pH7 |
Net charge of a peptide will change based on pH A net positive or negative charge tends to allow the peptide to be water soluble | Both the amine and carboxylic acid portion of an amino acid are pH dependent |
net charge= 2+, 3+ the better solubility proprotein? side chain? end- group and start to form peptide | pH1 |
net charge= O, 2+ | pH7 |
net charge= 2-, 1- | pH14 |
NSAIDs inhibit cyclooxygenase enzymes that are involved in the production of prostaglandins- cause pain, inflammation, fever and wide range of other effects | Eicosanoids are signaling molecules involved in immune and inflammation inhibit the enzyme that converts arachidonic acid into eicosanoids Aspirin, acetaminophen, and ibuprofen are all non-steroid anti-inflammatory drugs(NSAIDs) |
Both ion-dipole between water molecules and the heads of the phospholipids AND London dispersion between the tails of the phospholipids | Identify the intermolecular force that hold the bilayer together as a structure |
Increasing cholesterol and increasing the saturation and longer tails will all increase the amount of London dispersion forces between the tails and the cholesterol in the membrane which will make the cell more rigid | How the cell membrane flexibility changes depending on the structure of the phospholipids and the presence of cholesterol |
is the movement of molecules or ions high concentration to low concentration through the cell membrane | simple diffusion |
involves the movement of molecules or ions across a membrane against the concentration gradient require input of energy | Active transport |
usually have amine - [NH2] functional groups these amino acids all have side chains that contain nitrogen atoms that are willing to accept an H+ | Polar Basic NH3+ |
these amino acids both have side chains that contain carboxylic acid groups that are willing to donate an H+ (below pH) | Polar Acidic COOH- |
usually have only C-C and C-H bonds | Non Polar side chain |
these amino acids all have side chain with functional groups that contain a dipole resulting from two atoms with different electronegativities bonded to each other | Polar neutral - alanine, methionine, proline, phenylalanine |
Glutamine is in which class of amino acid? | Polar neutron acidic |
equilibrium for the donation of H+ (proton) * Above the pKa, H+ donate * @ the pKa: equilibrium | pKa |
BELOW: COOH- (pKa ~2) * Below the pKa, keep the H+ | NH3+ (pKa~9-10) |
COOH- <> COO- | NH3+ <> NH2 |
COO- (pH 3+) | pH 11+ : NH2 |
Increase pH , decrease H+ | * Acidic: loss much of proton (H+) * Basic: keep much of (OH-) |
Valine had @pH 7 | * COO- above pKa * NH3+ pH 1 below pKa: Acidic - [H:pKa~2] have amine group [NH3+~10] pH7 (lose H+) pH14 isopropyl group , just the alkane change - no characteristic of acid or basic |
Table 5.2 pKa values for the Ionizing Groups of the Amino Acids | |
Histidine | 8.33= pKa >>>> pI= |
Aspartic Acid | 6.00 |
Glutamic Acid | 3.86 |
Lysine | 10.79 |
Arginine | 12.48 |
for polar acidic and basic amino acids pI= average of the pKa of the COOH group and the pKa of the NH3+ group of the backbone | Ex Aspartic acid , pI= 3.86 + 2.09 /2 = 2 = Ex Lisine , pI = 8.95 + 10.97 /2 = |
N-terminus plus 1 charge C-terminus neutral | lose pH pKa~2 Ex that donate H+ |
monosaccharide are polyhydroxyl aldehydes and ketones are classified by functional groups -aldose-ketose by number C atom- triose- tetrose or both -aldopentose, ketohexose. | describe difference between mono-, oligo [2-10], polysaccharides [more than 10] |
explain classification system used to classified monosaccharides | |
Chiral molecules are not superimposable on mirror image most chiral molecule contains one or more chiral C atoms, C atom attached to 4#atoms or groups of atom a molecule with n chiral C atoms can have up to 2n stereoisomers | explain chiral molecule and chiral C atom |
Plant-polarized light can be used to distinguish enantionmers- one enantiomer rotates the light clockwise | dextrorotatory or + or D |
other rotates it counterclockwise | levorotatory or - or L |
D [ clockwise] on the right L [ counterclockwise] on the left | |
Aldopentose Keetotetrose | classified carbohydrates by functional group and #C |
Glycine with no asymmetric [chiral] C because it has 2 hydrogens attached to a-C | the only amino acid non-chiral ? |
2n | as the number of chiral C atoms increase, the total possible number of stereoisomers increase |
d-2-deoxyribose, aldohexoses d-glucose, d-galactose, keto-hexose d-fructose | common monosaccharide inclused aldopentosed-ribose |
deoxy sugars [ H replace OH] amino sugars [ NH2 replace OH] alcohol sugar [C-O has been reduced to an alcohol] carboxylic acid sugars [ aldehyde group or OH group has been oxidized to a carboxylic acid] | common observed monosaccharide derivatives |
reacting a monosaccharide with H2 in the present of Pt convert the aldose or ketose into an alcohol sugar. | |
Carbohydrates oxidized by this reagent are call [ reducing sugar] | Benedict's reagent contain Cu2+ oxidized aldehydes but will not oxidized alcohol |
aldehyde to alcohol | reduction |
enzymes catalyze the oxidation of aldehydes and alcohol groups of monosaccharides to form carboxylic acid sugars | oxidized |
useful for monitoring diabetes tests for sugars urine Ketones are able to rearrange into aldehydes to give a positive | Benedict's reagent |
carboxylate ion | all aldehyde are reducing sugars |
mutarotation | |
process called [mutarotation] | In solution, hemiacetal groups of a and b anomers can react to form aldehyde or ketone groups [ ring opens in the process, which react to re-form a and b anomes |
carboxylate ion | what is the product of the reaction between fructose and Benedict's reagent? |
pentoses and hexoses | intramolecular cyclization |
the former carbonyl C becomes a new chiral center | anomeric C |
the position of this group determines if the anomer is a or b | the former carbonyl oxygen becomes a hydroxyl group |
when an aldehyde and alcohol react | hemiacetal |
monosaccharides found in cyclic form cyclization results from an alcohol reacting with the carbonyl of an aldehyde or ketone | hemiacetal formation |
form aldehyde + alcohol | cyclic hemiacetals: monosaccharides contain both aldehydes [ or ketone] and an alcohol group |
glycine cysteine | neutral |
OH replace BY HYDROGEN ATOM DNA to RNA [ this group connect to backbone in 2nd position, #condition] more stable in reactive | deoxy sugars |
NH2 replace OH | amino sugar |
C-O has been reduced to an alcohol group | alcohol sugar |
an aldehyde group or an OH group been oxidized to an carboxylic acid | carboxylic acid sugars |
diastereomers refered as.. because they differat only one chiral C | epimers Ex: a-D-glucopyranose / a-D-galactopyranose |
enantionmers | D-glucose and L-glucose are |
at C-4 | D-galactose differs from D-glucose |
lacose gives milk its sweetness galactose converted to glucose when lactose is digested: + genetic disorder can inhibit this transformation | D-galactose combine with glucose to produce lactose |
ketose most often found in nature , present in fruit make up about 40% honey is key role in energy production | D-fructose is fruit sugar |
aldehyde [ aldonic acids] or alcohol group oxidized [ uronic acids] to a carboxylic acid | carboxylic acid sugar |
maltose 2a [1-4] linked glucose residues | disaccharide include |
2b[1-4] linked glucose residues lactose*a galactose residue linked b[1-4] to a glucose residue* and sucrose *an a glucose residue linked a,b[1-2] to b fructose residue | cellobiose |
is a disaccharide of D-glucose and D-fructose | sucrose, table sugar |
will not Benedict's reagent | an anomeric C in a glycosodic bond can't linerarize |
Cellulose Starch: Amylose, Amylopectin Glycogen Chitin | Polysaccharide of interest |
cellulose- cell wall of plants , starch , glycogen [animal], chitin | Homopolysaccharide |
hyaluronic acid, condroitin 4-sulfate, | Heteropolysaccharide |
the sugar on the right can freely interconvert between the cyclic structure and the straight chain form with an available aldehyde | reducing sugar |
both of the anomeric C involved in a glycosidic linkage so neither sugar unit in this disaccharide is able to convert to the straight chain structure | non-reducing sugar |
carboxylic acid predominated in human body | |
they [saturated] if they contain more saturated than unsaturated residues they [unsaturated] fatty acid residue predominated | triglyceride are triester form by combining 1 glycerol with 3 fatty acid |
vegetable oil [unsaturated triglyceride] liquids OIL tend to have lower melting point than fats | fat [solid] at room |
serve as energy storage molecule and provide thermal insulation, padding, buoyancy. | triglyceride |
involve in blood clotting | thromboxane |
affect muscle contraction | leukotrienes |
carboxylic acid and alcohol [ add water] | in acid hydrolysis of an ester , 2 product |
colloid formed by combining 2 liquids Ex mayonnaise | emulsion |
some anti-asthma block the production of leukotrienes | |
bilayer composed 20-25% of cholesterol. it embedded in the bilayer, reduces of bilayer, while strengthening the cell membrane | reduce the flexibility of the cell membrane |
progesterone , testosterone, estradiol | sex hormones |
cortisol, cortisone | adrenalcoticoid |
taurocholate and glycocholate | bile salts |