Protein Structure and Function

Question 1

Covalent bonds

Answer 1

Join building blocks into macromolecules like DNA.

Question 2

Non-covalent bonds

Answer 2

Stabilize macromolecule shapes crucial for cellular life.

Question 3

Macromolecules

Answer 3

Large biological molecules like proteins and nucleic acids.

Question 4

Dehydration reactions

Answer 4

Join monomers by removing water, forming polymers.

Question 5

ATP

Answer 5

Energy currency of the cell, vital for metabolism.

Question 6

Redox reactions

Answer 6

Chemical reactions involving electron transfer, essential for life.

Question 7

Amino acids

Answer 7

Building blocks of proteins, linked by peptide bonds.

Question 8

Peptide bonds

Answer 8

Link amino acids, formed by dehydration reactions.

Question 9

Protein structure levels

Answer 9

Include primary, secondary, tertiary, and quaternary structures.

Question 10

Globular proteins

Answer 10

Compact proteins, often soluble, with diverse functions.

Question 11

Fibrous proteins

Answer 11

Structural proteins, elongated and insoluble in water.

Question 12

Protein misfolding

Answer 12

Incorrect folding can lead to diseases like Alzheimer’s.

Question 13

Protein-protein interactions

Answer 13

Crucial for biological processes and cellular functions.

Question 14

N-terminal

Answer 14

Free amino end of a polypeptide chain.

Question 15

C-terminal

Answer 15

Free carboxyl end of a polypeptide chain.

Question 16

Zwitterions

Answer 16

Amino acids at physiological pH with no net charge.

Question 17

Chirality

Answer 17

Property of amino acids, except glycine, having two forms.

Question 18

Hydrophobic amino acids

Answer 18

Tend to be inside globular proteins, avoiding water.

Question 19

Hydrophilic amino acids

Answer 19

Able to form hydrogen bonds, found on protein surfaces.

Question 20

Disulfide bonds

Answer 20

Covalent bonds formed between cysteine residues.

Question 21

Secondary structure

Answer 21

3D structure formed by hydrogen bonds in polypeptides.

Question 22

Alpha helix

Answer 22

Tightly coiled structure with R groups projecting outward.

Question 23

Beta sheets

Answer 23

Formed by adjacent strands linked by hydrogen bonds.

Question 24

Random coil

Answer 24

Irregular arrangement of polypeptide chains.

Question 25

Motifs

Answer 25

Specific arrangements of secondary structure elements.

Question 26

Leucine zipper

Answer 26

Example of an alpha helical protein involved in gene regulation.

Question 27

Fibroin

Answer 27

Silk protein with antiparallel beta sheet structure.

Question 28

Hydrogen bonding

Answer 28

Interactions stabilizing secondary protein structures.

Question 29

Tertiary structure

Answer 29

Overall 3D arrangement of protein atoms.

Question 30

Native fold

Answer 30

Specific conformation enabling biological function.

Question 31

Cystine

Answer 31

Dimer of cysteine linked by disulfide bond.

Question 32

Insulin

Answer 32

Hormone stored as inactive hexamer, active as monomer.

Question 33

Protein domains

Answer 33

Independently stable structural motifs in proteins.

Question 34

Kinase domain

Answer 34

Common protein domain involved in phosphorylation.

Question 35

Quaternary structure

Answer 35

Association of multiple polypeptide chains.

Question 36

Homo-multimers

Answer 36

Complexes of identical polypeptide chains.

Question 37

Hetero-multimers

Answer 37

Complexes of different polypeptide chains.

Question 38

Primary structure

Answer 38

Linear sequence of amino acids in a protein.

Question 39

Protein diversity

Answer 39

Variety of protein structures reflecting function.

Question 40

α-Keratin

Answer 40

Coiled-coil fibrous protein providing structural support.

Question 41

Membrane proteins

Answer 41

Proteins interacting with lipid bilayers.

Question 42

G-protein-coupled receptors (GPCRs)

Answer 42

Large family of membrane proteins with seven domains.

Question 43

Ligand

Answer 43

Small molecule that binds to a protein.

Question 44

Induced fit model

Answer 44

Conformational change upon ligand binding.

Question 45

Enzymes

Answer 45

Proteins that catalyze biochemical reactions.

Question 46

Active site

Answer 46

Region where substrate binds on an enzyme.

Question 47

Transition state

Answer 47

Intermediate state during a chemical reaction.

Question 48

Inhibitors

Answer 48

Molecules that decrease enzyme activity.

Question 49

Peptidoglycan

Answer 49

Structural component of bacterial cell walls.

Question 50

Penicillin

Answer 50

Antibiotic that irreversibly inhibits transpeptidase.

Question 51

Neurodegenerative diseases

Answer 51

Diseases linked to protein misfolding and aggregation.

Question 52

Lewy bodies

Answer 52

Intraneuronal aggregates associated with Parkinson's disease.

Question 53

Alpha-synuclein

Answer 53

Protein linked to Lewy bodies in Parkinson's.