Proteins - AP Biology
- What is the role of myosin?
- Motor protein involved in muscle contraction. Converts chemical energy to mechanical force for movement.
- Which amino acid is most commonly found in collagen?
- Glycine. Smallest amino acid allows tight turns in collagen helix.
- What is the function of rhodopsin?
- Photoreceptor protein in the retina. Light-sensitive protein that initiates vision in rod cells.
- Identify the protein responsible for oxygen storage in muscles.
- Myoglobin. Single-chain protein that stores oxygen in muscle tissue.
- Which bond is formed between the carboxyl and amino group of two amino acids?
- Peptide bond. Dehydration reaction creates covalent linkage in protein backbone.
- Identify a protein involved in immune response.
- Antibodies. Immunoglobulins that provide specific defense against pathogens.
- What is the role of elastin?
- Provides elasticity to tissues. Allows tissues to stretch and return to original shape.
- Identify the technique used to determine protein structure.
- X-ray crystallography. Uses X-rays to reveal atomic-level protein structure details.
- Which structure level involves alpha helices and beta sheets?
- Secondary structure. Formed by hydrogen bonds between backbone atoms in polypeptide.
- What is the effect of pH on protein structure?
- Can lead to denaturation. Extreme pH disrupts hydrogen bonds and ionic interactions.
- Identify a protein involved in cell signaling.
- Receptors. Membrane proteins that detect and respond to chemical signals.
- What is the quaternary structure of proteins?
- Assembly of multiple polypeptide chains. Multiple polypeptides combine to form functional protein complexes.
- What is the role of chaperone proteins?
- Assist in protein folding. Prevent misfolding and help proteins achieve proper 3D structure.
- Identify one example of a globular protein.
- Hemoglobin. Compact, spherical protein with complex tertiary structure.
- What is the role of hemoglobin?
- Transport oxygen in blood. Iron-containing protein binds and carries oxygen molecules.
- What type of interaction stabilizes tertiary protein structure?
- Hydrophobic interactions, disulfide bridges. Side chain interactions create and maintain 3D protein shape.
- What is the impact of temperature on enzyme activity?
- High temperature can denature enzymes. Extreme heat breaks bonds that maintain enzyme active site.
- Which structure is the sequence of amino acids in a polypeptide?
- Primary structure. Foundation level that determines all higher structural levels.
- What are enzymes?
- Proteins that act as biological catalysts. Speed up biochemical reactions by lowering activation energy.
- What is a protein domain?
- Functional unit within a protein. Independently folded region with specific structure and function.
- Which enzyme is involved in DNA replication?
- DNA polymerase. Synthesizes new DNA strands during cell division.
- Which amino acid initiates protein synthesis?
- Methionine. Start codon AUG codes for this first amino acid.
- Which amino acid has a sulfur atom in its side chain?
- Cysteine. Only amino acid capable of forming disulfide bonds.
- What is denaturation in proteins?
- Loss of structure and function. Disruption of non-covalent bonds destroys protein's native shape.
- What is the role of insulin?
- Regulates blood glucose levels. Hormone that lowers blood sugar by promoting glucose uptake.
- Identify a method to separate proteins based on size.
- Gel electrophoresis. Separates proteins by molecular weight through porous gel matrix.
- What determines the primary structure of a protein?
- Amino acid sequence. Linear order of amino acids determines all higher-level structures.
- Identify the bond formed between cysteine residues.
- Disulfide bond. Covalent sulfur-sulfur bridge stabilizes protein structure.
- What is the function of antibodies?
- Bind to antigens to neutralize them. Y-shaped proteins that recognize and bind specific foreign substances.
- Identify one example of a fibrous protein.
- Collagen. Structural protein with elongated, rope-like quaternary structure.
- Which protein structure is affected by denaturation?
- Secondary, tertiary, quaternary structures. Higher-order structures unfold while primary structure remains intact.
- Name the four levels of protein structure.
- Primary, secondary, tertiary, quaternary. Hierarchical organization from amino acid sequence to complex 3D shape.
- Identify the bond that links amino acids in proteins.
- Peptide bond. Covalent bond formed by dehydration synthesis between amino acids.
- What is the monomer unit of proteins?
- Amino acids. Basic building blocks that link together to form protein chains.
- Identify the protein that acts as a buffer in blood.
- Albumin. Most abundant blood protein that maintains osmotic pressure.
- What is the role of ferritin?
- Stores iron in cells. Storage protein that safely sequesters iron for cellular use.
- What is the role of catalase?
- Breaks down hydrogen peroxide. Antioxidant enzyme that protects cells from oxidative damage.