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Cells & Tissues
Chemistry of the Cell-Test #1
Front | Back |
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What are the 6 Macronutrients of the cell? | Carbon, Hydrogen, Oxygen, Nirtrogen, Sulfur, Phosphorus |
What are the elements imp. to life? | Hydrogen, Oxygen |
What are the trace elements? | Iron, Zinc, Magnesium, Cobalt |
Bond | elements combine to complete outer shell of elect. for each element |
Covalent Bond | Shared pair of electrons b/w 2 atoms |
Polar Covalent Bond | One atom has the shared elect. more (electronegative "electron greedy) than the other atom. Oxygen & Nitrogen most electron negative atoms. H20 ex. of polar covalent bond. |
Nonpolar Covalent Bond | elect. shared equally b/w atoms |
Ionic Bond | Very strong bonds. Electronegative element removes electron from another atom. Molecules frequently form crystals that are soluble in water |
Example of Ionic Bond | chlorine and sodium |
Hydrogen Bond | weaker than covalent or ionic bonds. Are stable in large molecules w/ many hydrogen bonds. Imp. in secondary structure of proteins. |
van der Waals interactions | weaker than hydrogen bonds. Found in macromolecules. interaction b/w aromatic compounds. distance is crucial; not too close/not too far. Found in interaction b/w stacked bases in DNA |
Hydrophobic interactions | In interior of molecules sequestered from water on exterior. b/w nonpolar molecules that come together to limit exposure to water-lipids. More stable when hyrdrophobic regions are near one another. |
Carbon | Tetravalent-forms 4 covalent bonds. Side groups (functional groups) increases diversity. Common bonds w/ carbons, oxygen, hyrdrogen, and nitrogen. Forms -, =, triple bonds. Forms stable compounds-require high energy to break bond. |
Asymmetric Carbon | carbon w/ 4 diff. attached groups. Can have 2 diff. spatial arrangements. Stereoisomers (mirror images) |
Water | Makes up 75-85% of cell weight-most abundant component. Is a polar molecule. POLARITY: bond angles b/w O & H; separation charges-one end more negative than other; affects cohesiveness, heat capacity, & solvent prop. |
Water | Cohesiveness: hydrogen bonds b/w water molecules; increases surface tension, boiling point, etc |
Water | Heat Capacity: specific heat high b/c of hyrdrogen bonds; amt absorbed/gram to increase temp 1°C. can absorb heat released during chemical rxns. |
Water | Solvent: dissolves variety of solutes; relatively inert; polarity allows it to hyrdate + or - charged ions & polar molecules (hydrophilic water loving) ; nonpolar molecules insoluble in water (hydrophobic) disrupt bonds b/w water molecules so are excluded |
What is an amphipathic molecule? | Macromolecules that have polar and non polar regions |
What do amphipathic molecules form? | Micelles |
Macromolecules | A molecule containing a very large # of atoms. Measured in kilodaltons. Linear molecules. Imp. structural & functional components of cells. |
What are macromolecules composed of? | Proteins, nucleic acids, lipids, polysaccharides |
Synthesis of macromolecule from smaller molecules | 1.Polymerization: bonding monomers "sngl units" together to form polymers. Each addtn releases H2O-condensation. 2.Components must be activated-requires ATP energy. 3.Components attached to carrier molecules-grwth always @ end of a sgl mlcule 4.Direction |
Macromolecules | Contain the necessary info. for proper folding & organiz. essential in structure |
Macromolecule Protein Assembly | As its being translated on ribosome it undergoes self-assembly=Polypeptide necessary for proper folding and final config. to give correct shape. Assisted self-assembly by chaperones=used for larger, more complex proteins composed of more than one polypep |
Macromolecule Protein Assembly cont'd | Asstd. self-assembly must have assistance to form final shape. Chaparone does not form part of the protein. transiently binds to exposed parts of polypep. & prevents inappropriate interactions |
What are the 4 classes macromolecules? What are the building blocks of each? | PROTEINS-Amino Acids NUCLEIC ACIDS-Nucleotides LIPIDS-Fatty Acids POLYSACCHARIDES-Sugars |
How many types of amino acids are found in celluar proteins? | 20 |
Amino acids are linked by what type of bond? | A peptide bond (covalent bond) formed b/w amine group of one amino acid and carboxyl group of next amino acid |
Amino acids are classified by what? | According to nature of unique functional group |
What are the 3 types of amino acids? How many belong to each class? | 9 Nonpolar hydrophobic amino acids; 6 Polar uncharged amino acids; 5 Polar charged amino acids |
What do the 9 nonpolar hyrdophobic amino acids mostly lack? | Oxygen & Nitrogen in functional group |
How many polar uncharged amino acids are there? | Six amino acids and they are hydrophilic |
How many polar charged amino acids are there? | A total of 5. 2 ACIDIC and 3 BASIC hyrophilic amino acids. |
Amino acids can exist in two stereoisomers (D and L forms) due to what presence? | The presence of asymmetric carbon. |
What are polypeptides? | Chains of amino acids joined by peptide bonds. |
What is Translation? | Protein synthesis or the specific order in which each polypeptide is formed. |
What are the two ways that proteins may be composed of? | Either a sing polypeptide (monomeric) or multiple polypeptides (multimeric) |
What are the 4 hierarchical levels of organization in a polypeptide? | Primary, Secondary, Tertiary, & Quartnary Structures |
The Primary Structure is based on what? | Based on amino acid sequence. The order of amino acids in the linear sequence of the protein |
What happens in the level of structure in a Secondary Structure? | 2 types of shapes form either an α-helix or a β-pleated sheet. The form it takes on is determined by hydrogen bonding within the polypeptide. |
A Tertiary Structure has what type of shape? | A 3-D shape due to the long-distance interactions within polypeptide due to hydrogen bonds & disulfide bonds. Polar covalent or charged are hydrophilic-exterior. Nonpolar are hyrdrophobic-interior |
Quartenary Strucure has what shape? | A multiple subunit of proteins formed by the interaction of multiple polypeptides to form multimeric structures. Example-hemoglobin |
What are the diff. functions of proteins? | Enzymes-catalyze metabolic reactions; Structural-structural components of cell; Motor-ex. sperm; Transport; Storage; Signal; Receptors; Regulate Gene Expression-by activating or repressing |
What are lipids? | Are macromolecules that are nonpolar and have fatty acids as they're building blocks. They are hyrdrophobic (nonsoluble in water) ; soluble in nonpolar solvents; mostly hyrdrocarbon chains containing C and H; some have polar regions-amphipathic |
What is the definition of amphipathic? | To have both polar and nonpolar regions |
What are the diff. classes of lipids? | Fatty acids, triglycerides, phopholipids, sphingolipids, glycolipids, steroids, and terpenes |
What are Triglycerides? | A type of lipid that is considered a true fat. It is used for energy storage and a very efficient form of energy. Glycerol + 3 fatty acids |
What are the 3 types of triglycerides? | Fatty acids, Saturated fatty acids, and Unsaturated fatty acids |
Whats the structural composition of a fatty acid? | An unbranched hydrocarbon chain with carboxyl group |
What's the structural composition of a saturated fatty acid? | All singe bonds. Most fats are saturated fatty acids and are SOLID at room temp. |
What's the structural composition of Unsaturated Fatty Acids? | Composed of one or more double bonds. Oils are mostly unsaturated fatty acids and are LIQUID at room temp. |
What is a phospholipid? | A type of lipid that is amphipathic (hyrophobic & hyrdraphilic) and as such tends to self-assemly into membranes. Phosphate group replaces one fatty acid and they usually have alcohol linked to phosphate. Polar head group creates amphipathic structure |
What is a sphingolipid? | A type of lipid that is also amphipathic and primarily found in NEURO tissue or membranes. Its based on sphingosine-an amine alcohol. |
What is a Glycolipid? | A type of lipid that is amphipathic & found in the membranes of nerve tissue or on the outer surface of plasma membranes. They act as recognition types for other molecules to be attracted to them. |
What is a steroid? | A type of lipid that is amphipathic and found in plasma membranes and is the source of all steroid hormones like androgens, estrogens, and cortisol. |
What is the most common type of steroid? | Cholesterol which helps keep fluidity |
What are terpenes? | A type of lipid used in the synthesis of Vit. A, coenzyme Q, carotenoid pigments |
What are polysaccharides? | Types of sugars that are storage and structural molecules. Made of monomers of simple sugars (monosaccharides) |
Starch & Glycogen are used for what in polysaccharides? | For storage |
The polysaccharide Cellulose is used for what? | For structural purposed only in PLANTS |
What are the diff. types of monosaccharides? | Aldosugars, Ketosugars, Hexose Sugars (most common=glucose) Pentose Sugars |
What are Disaccharides? | Two monosaccharides linked by glycosidic bond (ex. sucrose-table sugar & lactose-milk sugar) |
Nucleic acids are a polymer of what? | Nucleotides |
Nucleotides are made up of what? | Nitrogenous base; Pentose Sugar & Phosphate |
Nucleic Acids are synthesized by what? | By a phosphodiester bond b/w phosphate group & sugar of adj. nucleotide |
The synthesis of a nucleotide is in what direction? | 5' to 3' direction |
What are nucleotides used for in the cell? | Storage of genetic info-DNA; expression of genetic info.-RNA; source of utilizable chemical energy in cell |
What type of bond connects the monomers of Proteins, Nucleic Acids, Polysaccharides? | Protein-peptide bond; Nucleic Acids-phosphodiester bond; Polysaccharide-Glycocidic Bond |