Question | Answer |
What are 5 reasons that carbon is particularly well suited to be the backbone of organic molecules? | 1) it forms both covalent & ionic bonds 2) its covalent bonds are irregularly arranged in 3 dimensional space 3) its covalent bonds are the strongest bonds 4) it can bond to atoms of a large number of other elements 5) all bonds it forms are polar |
What are hydrocarbons? | Organic compounds consisting of only carbon and hydrogen |
What are isomers? | One of two or more chemical compounds having the same chemical formula but different structural formula |
Why do isomers have different properties? | Because they have different structures |
How else do isomers differ from one another? | They do not have the same physical or chemical properties, and have different common names |
How can cells distinguish between isomers? | One can be more biologically active and others are not |
What are the 3 types of isomers? | 1) structural isomers 2) geometric isomers 3) enantiomers |
What is a structural isomer? | a type of chemical formula that shows the spatial arrangement of the atoms in a molecule |
What is a geometric isomer? | One of two or more chemical compounds having the same arrangement of covalent bonds but differing in the spatial arrangement of their atoms of groups of atoms |
What is an enantiomer isomer? | two isometric chemical compounds that are mirror images of each other |
What are hydrocarbons? | An organic compound, non-polar molecule, or functional group composed of only hydrogen and carbon atoms |
What are hydrophobic interactions? | The tendency of hydrophobic substances to cluster together due to strong cohesive interactions among surrounding water molecules |
What is a functional group? | A group of atoms that determine the types of chemical reactions and associations in which the compound participates |
Functional groups form associations with what kinds of bonds? | They form associations with hydrogen and ionic bonds, with other molecules |
Polar and ionic functional groups are considered to be __________________ | Hydrophilic |
Why are polar and ionic functional groups considered to be hydrophilic? | Polar and ionic functional groups are considered to be hydrophilic because they associate strongly with polar water molecules |
What are the 4 major groups (or polymers) of organic compounds found in living systems? | 1) carbohydrates 2) lipids 3) proteins 4) nucleic acids |
In carbon containing inorganic molecules, carbon is bonded to something other than __________________ and ___________________ | Carbon and hydrogen |
The ____________atom forms ______________ with a greater number of different elements than does any other type of atom | Carbon, bonds |
The addition of _______________ containing atoms of other elements especially nitrogen, oxygen, phosphorus, and sulfur can profoundly change the properties of an organic molecule. | Chemical groups |
How many valence electrons does carbon have? | 4 |
Individual carbon atoms can form up to how many bonds with other atoms? | 1, 2, 3, and 4 |
What three forms can hydrocarbon molecules exist as? | Branched chains, unbranched chains, and rings |
Isomers have the same molecular formula, but different _______________ | Structures |
What kind of isomers are compounds that differ in the covalent arrangements of their atoms? | Structural isomers |
True or false: Some chemicals could only be made of living things because they possess a vital, special character unique to life. | False |
How many bonds can carbon form? | 4 |
What shape are carbon single bonds? | Pyramid shapes |
What shape are carbon double bonds? | Linear |
What shape are carbon triple bonds? | Linear |
Why are some building blocks of large molecules called functional groups? | Because they have specific functions and atomic groups |
What is the molecular formula for carboxyl group? | -COOH |
What is the following functional group:
O
II
C
R^OH | A carboxyl group |
What is located in the middle of a carboxyl group?
O
II
R^OH | A carbon |
What do carboxyl groups do with their hydrogens? | They give up their hydrogen to form things that are carboxylic |
What does a carboxyl group and an amino group form? | They form amino acids |
What is the following functional group?
O
II
R^R | A carbonyl group |
Where can a carbon be located in a carbonyl group? | In the middle or end |
If the carbon of a carbonyl group is located in the middle, what is it called? | A keytone |
If the carbon of a carbonyl group is located at the end, what is it called? | An aldehyde |
What is the following functional group?
H
I
C--H
R^H | A methyl group |
How many hydrogens are in a methyl group? | 3 |
What is the molecular formula for a methyl group? | -CH3 |
What are the differences between the three types of isomers? | Structural isomers differ in the covalent arrangements of their atoms, geometric or Cis-trans isomers differ in the spatial arrangement of atoms, enantiomers are isomers that are mirror images of each other |
Can cells distinguish between the three isomers? How? | Yes, because some are more biologically active |
What is the following functional group?
. .
N -H
/ \
R H | An amino group |
What is the key element that is needed to make an amino group? | Nitrogen |
What is the following functional group?
O
II
P
/ I \
O- O- O- | A phosphate group |
Which functional group is on the end of ATP? | Phosphate group |
What is the following functional group?
O
/ \
R H | A hydroxyl group |
What is a polymer? | Large macromolecules that are made up of monomers |
What are monomers? | The building blocks of polymers |
How are polymers built? | Through dehydration |
What is a dehydration reaction? | The removal of water H2O, forming a covalent bond in the middle (peptide bond) |
Each time you want to attach an amino acid, you must ____________ a water. | Remove |
What is a hydrolysis reaction? | Breaking down proteins and making amino acids by adding water |
How are proteins built? | Through dehydration reaction |
What two functional groups do amino acids always have? | Carboxyl and amino groups |
Proteins are one of the 4 main ____________ (organic compounds) | Polymers |
Through what reaction are nucleic acids built? | Dehydration reaction |
What are the two classes of nucleic acids? | RNA and DNA |
RNA and DNA are considered to be _______________ | Polymers |
What are 3 things that a nucleotide of DNA is made of? | Base, sugar, and a phosphate |
What are some differences in the structures of an amino group? | The R group, as well as the charge |
Is amino acid considered to be a polymer or a monomer? | A monomer |
What are proteins made up of? | Amino acids, which are monomer |
Nucleic acids are ____________ or nucleotides. | Polymers |
How many amino acids are needed for a human to survive? | 20 |
Amino acids are joined by _________________ | Peptide bonds |
How does a peptide bond form? Through what reactions? | Peptide bonds form through condensation/dehydration, as well as the amino group of one amino acid and the carboxyl group of another |
When are amino acids formed? | When the OH molecule on the end joins with a H from the amino group |
What are the four levels of protein structure? | 1) primary 2) secondary 3) tertiary 4) quaternary |
How would you describe a primary structure of proteins? | It refers to the identity and order/sequence of the amino acids Ex. sickle cell anemia is caused by a single amino acid substitution in the protein hemoglobin. EVEN SMALL CHANGES HAVE A MAJOR IMPACT! |
How would you describe the secondary structure of proteins? | It refers to the folding of a protein due to hydrogen bonds which form between amino and acid groups on different amino acids within a protein |
What are the two common shapes of a secondary structure protein? | Alpha-helices and beta-pleated sheets |
What are alpha-helices? | A shape of a secondary structure protein that looks like spirals |
What are beta-pleated sheets? | A shape of a secondary structure protein that looks like an accordion-folded paper |
What holds the helices and neighboring sheets together? | Hydrogen bonds |
How would you describe the tertiary structure of protein? | It refers to the folding of a single amino acid chain due to its interactions between the R groups of its amino acids with each other or the solvent. |
Tertiary structures are affected by _________________ . For example, non-polar R-groups get pushed by water toward each other | Polarity |
How would you describe the quaternary structure? | It refers to the bonding between multiple amino acid chains to form a single functional unit. |
True or false: Hemoglobin is an example of a quaternary structure. | True |
What is unique about quaternary structure? | It exhibits secondary and tertiary folding |
True or false: Some proteins fold themselves, based on random movements followed by hydrogen bonding or ionic attraction | True |
Some proteins require guidance from _________________ to fold correctly. | Chaperone |
What is being looked at about proteins in reference to Domains? | The fact that different parts have different functions. For example, you have two domains where one part of a protein may connect with another protein & another may connect with DNA. Or one type of domain where two different proteins will bind with DNA |
In reference to proteins, what is denaturation? | When unnatural conditions, such as unusual temperatures, pH, solvents, may cause them to lose their natural shape. |
What is an example of denaturation? | Paperclips folded or unfolded and tangled. Also, the protein albumin in eggs undergoes denaturation & loss of solubility when the egg is cooked |
What are lipids classified by? | Their solubility |
What are lipids? | Organic molecules/polymers which are insoluble in water but are soluble in non-polar solvents |
What are the functions of lipids? | The capture energy, store energy, role in structure, signals and communicates between or within cells, and protection |
What are Caretenoids, chlorophyll, and retinal? | Several pigments that are lipids |
Which of the three lipid pigments (Caretenoids, chlorophyll, and retinal) allow the capture of the sun's energy by some organisms, which can be stored or used later? | Caretenoids and chlorophyll |
What does retinal do with the energy in light? | It captures the energy in light and indirectly leads to a signal in a nerve, allowing vision |
What is the most common lipid? | Triglyceride |
How are lipid triglycerides made? | Condensation/dehydration reactions between 3 fatty acids and glycerol |
What are the 3 fatty acids? | 1) saturated fat 2) mono-unsaturated fat 3) poly-unsaturated |
What functional group is part of the fatty acid? | Carboxyl |
Are lipids hydrophilic or hydrophobic? | Hydrophobic |
Triglycerides consist of _______________ and ______________. | Oils and fats |
What are the subunits of triglycerides? | Glycerol and fatty acids |
What are the three main parts of a fatty acid? | 1) Hydrocarbon chain 2) Methyl group 3) |
Why do lipids tend to by hydrophobic? | Because they are non-polar, and they have little oxygen and more carbon and hydrogen. |
What are the functional groups of a fatty acid? | A long hydrocarbon chain, a carboxyl group at one and, and a methyl group at the other end |
What are the functional groups of the glycerol? | 3 Hydroxyl groups |
A fatty acid that has single carbon bonds are considered saturated or unsaturated? | Saturated (solid at room temperature) |
A fatty acid that has a double carbon bond are considered to be saturated or unsaturated? | Unsaturated (liquid at room temperature) ex. transfat |
How does a triglyceride form between glycerol and 3 fatty acids? | 3 fatty acids have to bond with a glycerol molecule through dehydration synthesis |
What is the difference between a triglyceride and a phospholipid? | Triglyceride contains 3 fatty acids and a glycerol, while phospholipid contains hydrocarbon chain followed by a phosphate group and only two fatty acids |
True or false: The head of the phospholipid is hydrophilic. | True |
Is the fatty acid tail of the phospholipid hydrophilic or hyrophobic? | Hydrophobic |
How would you describe an amphipathic molecule? | A phospholipid with both a hydrophobic end and a hydrophilic end |
Unlike lipids, hydrophilic functional groups typically contain _____________ atoms, which make them more soluble in water. | Oxygen |
What functional group forms bridges to help stabilize a protein's quaternary structure? | Sulfhydryl |
What is responsible for the alpha-helical structure of proteins? | Hydrogen bonds |
If tyrosine and isoleucine undergo condensation, where does the new bond form? | Between carbon of the carboxyl group ad the nitrogen of the amino group |
How would you describe the tertiary structure of a protein molecule? | A three-dimensional shape of an individual polypeptide chain |
What is the purpose of molecular chaperones | To assist in the folding of other molecular proteins |
What type of protein accelerates the thousands of different chemical reactions that take place in an organism? | Enzymes |
What is the purpose of regulatory proteins? | To control the expression of specific genes |
What linkage is paired with a nucleic acid? | Phosphodiester linkage |
What is the difference between DNA and RNA? | DNA comprises the genes, while RNA is a direct participant in the process of protein synthesis |
Why is ATP important in living organisms? | It can transfer some of its energy to other organisms |
What organic molecule is the primary structural component of cell membranes? | Phospholipids |
Which organic compound is not only responsible for energy storage but also can provide thermal insulation? | Lipids |
Why are hydrocarbons considered hydrophobic? | The covalent bonds between hydrogen and carbon re nonpolar |
Amyloplasts are organelles that store ______________. | Starch |
What carbohydrate energy storage molecule is found in animal liver and muscle cells? | Glycogen |
What is a property of unsaturated fats? | They are liquid at room temperature |
Most organic molecules are flexible because the carbon-to-carbon bond has ________________________. | Has freedom of rotation |
What are two functional groups that are polar? | Carbonyl and hydroxyl |
______________ is the most abundant carbohydrate on Earth. | Cellulose |
One end of a phospholipid is hydrophobic because it is composed of ____________________. | Fatty acids |
Within the structure of RNA, what nitrogenous base pairs with cytosine? | Guanine |
DNA's sugar-phosphate backbones are joined by what type of connections? | Phosphodiester linkages |
Which type o polypeptide structure has a helical coil with elastic proteins? | Secondary |
Which part of human blood is an example of a protein with a quaternary structure? | Hemoglobin |
When a carboxyl group releases a hydrogen, the molecule becomes _____________ charged. | Negatively |
A polymer can be broken down into a monomer with the addition of water through a process called _______________. | Hyrolysis |
How many amino acids can make up a protein? | 20 |
True or false: Some fatty acids are essential nutrients to humans and must be consumed because the body cannot synthesize those fatty acids. | True |
Many monounsaturated or polyunsaturated fatty acids remain as liquids at roo temperature because the covalent bonds within their structure are bent, preventing _________chains from aligning to one another. | Hydrocarbon |