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50 Cards in this Set
- Front
- Back
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What is a peptide bond?
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A peptide bond forms between two amino acids at the amino group of one molecule, and the carboxyl group of the other.
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What is the general name of an amino acid polymer?
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peptide
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What is the chemical formula of an amino group?
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-NH2
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What is the chemical formula of a carboxyl group?
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-COOH
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What are fibrous proteins?
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Fibrous proteins are found as pleated sheets or in long chains of helices. Ex. Collagen is a fibrous protein.
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What are globular proteins?
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Globular proteins have amino acid chains that fold back on themselves to create a complex structure containing pockets, channels, or protruding knobs.
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How is protein tertiary structure categorized?
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In two types of large molecules: globular, and fibrous.
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Name two characteristics of fibrous proteins.
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They are insoluble in water, and form structural components of cells and tissues.
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How are globular proteins formed?
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Partly from the covalent bonds between amino acids, and partly from hydrogen bonds, van der Waals forces, and ionic bonds.
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Name two properties of globular proteins.
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They are soluble in water, and also serve as enzymes that increase the rate of chemical reactions.
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How many amino acids commonly occur in nature?
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twenty
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How many amino acids are esesntial amino acids?
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nine
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What are essential amino acids?
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Amino acids that the body cannot synthesize. The nine must be obtained from dietary proteins.
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What are saturated fatty acids?
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Fatty acids are saturated if there are no double bonds between carbons.
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Are saturated or unsaturated fatty acids solid at room temperature?
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The more saturated a fatty acid is, the more likely it is to be solid at room temperature.
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What elements are found in lipids?
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Carbon, Hydrogen, and Oxygen
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Are lipids polar or nonpolar? hydrophillic or hydrophobic?
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nonpolar; hydrophobic
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What are the three lipid-like categories?
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phospholipids, steroids, and eicosanoids
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What type of molecule is the backbone found in all lipids?
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glycerol (3-carbon molecule)
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What is the chemical formula of a phosphate group?
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-H2PO4
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What groups form fatty acids?
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glycerol + fatty acids
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What is the chemical composition of fatty acids?
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long chains of carbon bound to hydrogen atoms, with a carboxyl group at one end.
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How is glucose stored in animals? in plants? in bacteria/yeast?
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Animals store glucose as glycogen, plants as starch, and bacteria as dextran.
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What is the general formual of carbohydrates?
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CH2O; for each carbon there are two hydrogens and one oxygen.
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What are the two pentase (5 carbon) sugars?
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ribose, and deoxyribose.
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What are free radicals?
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Free radicals have at least one unpaired electron, making them unstable
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What are antioxidants?
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Substances that prevent damage to our cells by giving up electrons without becoming free radicals.
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What is a mole?
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A mole is expressed as 6.02x10^23
One mole of a substance has the same number of particles as one mole of any other substance. A dozen eggs has the same number of items as a dozen roses. |
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How is the molecular mass of a molecule calculated?
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Multiply the atomic mass of each element in the molecule by the number of atoms in the element in the molecule, then add the results.
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Define gram molecular mass.
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The mass of one mole of a substance is equal to the atomic or molecular mass of the substance expressed in grams.
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What are the three parts of a nucleotide?
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a phosphate (PO4) + base + pentose (5-carbon sugar)
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What are the purine bases?
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adenine, guanine
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What are the pyrimidine bases?
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cytosine, thymine (DNA only), and Uracil (RNA only)
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Draw the bond structure of an amino acid.
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COOH-
H-C-R -NH2 |
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Describe the core structure of an amino acid.
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All amino groups consist of a carbon attached to an amino group, a carboxyl group, a hydrogen, and a variable R group.
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How do amino acids differ from carbohydrates and lipids?
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From the presence of Nitrogen
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What is a conjugated protein?
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Protein molecules combined with any other kind of biomolecule. Ex. lipoproteins (lipid + protein).
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Define primary structure.
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The sequence of amino acids in a polypeptide or protein chain.
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Define secondary structure.
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The shape or spatial arrangment a peptide takes on as it is synthesized due to interactions (bonding/attaction) between its chemical groups.
The most commonly occuring secondary structures are the alpha-helix, beta-sheet, and beta-turn. |
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Name the six functions of proteins.
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1. Enzymes
2. Transporters 3. Structural proteins: intracellular (cytoskeleton, contractile proteins) and extracellular (collagen, elastin, reticulin) 4. Chemical mediators, such as neutrotransmitters, hormones, cytokines etc. 5. Membrane channels, such as ion channels, aquaporins 6. Energy |
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How many combinations of triplet nucleotides are possible?
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64
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What is necrosis?
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Cells die from physical trauma, toxins, or lack of oxygen when their blood supply is cut off.
Necrosis releases digestive enzymes when a cell dies that damages neighboring cells. |
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What is apoptosis?
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Apoptosis is a tidy form of cell death that removes cells without disrupting their neighbors.
Apoptosis is also refered to as programmed cell death. |
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What are the five functional types of epithelia?
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1. Protective
2. Secretory 3. Transporting 4. Ciliated 5. Exchange |
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Do Pyrimidines have a double or single nitrogen-containing ring?
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single
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Do Purines have a double or single nitrogen-containing ring?
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double
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What is a gap junction?
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The simplest form of cell-cell junctions in which bridges between adjoining cells allow chemical and electrical signals to pass from one cell to the next. The channels open and close to regulate the movement of small molecules and ions through them.
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What are tight junctions?
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In tight junctions teh cell membranes of adjacent cells partly fuse together with the help of proteins. These junctions create a barrier that prevents most substances from passing through (such as the blood brain barrier separating intracellular and extracellular fluid of the brain)
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What is the strongest type of cell-cell junction?
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Desmosomes
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What are the two forms of cell-cell anchoring junctions?
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desmosomes and adherens junctions
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