BSI Lecture 3 Protein Function Flashcards Preview

Pharmacy BSI > BSI Lecture 3 Protein Function > Flashcards

Flashcards in BSI Lecture 3 Protein Function Deck (50):
1

6 Types of Protein Function

1. structural
2. regulatory
3. contractile
4. immunological
5. transport
6. catalytic

2

Structural

form structural framework

3

Regulatory

alters cell function (hormones, neurotransmitters, receptors)

4

Contractile

allows shortening of muscle cells

5

Immunological

aid responses that protect body against foreign substances and invading pathogens

6

Transport

carry vital substances throughout body

7

Catalytic

enzymes that regulate biochemical reactions

8

Proteins interact with what molecule(s) to carry out their functions?

ligands

9

True or False? Ligands have to fit perfectly into their binding site.

True

10

What holds the ligand in place?

Many bonds between the ligand and the side chains of the proteins in binding site.

11

What types of bonds and attractions hold the ligand into the binding site?

Non-covalent bonds (hydrogen bonds, ionic bonds, hydrophobic interactions, and Van der Waals attraction)

12

What determines the function of a protein?

Its conformational shape

13

What determines the types and locations of binding sites

shape

14

True or False? If the conformational shape of a protein changes, the binding site may change.

true

15

What 2 things may happen in regards to the ligand and protein if the conformational shape of the protein changes?

1. ligand will not bind
2. not enough bonds will be made to hold the ligand in place

16

Define: Denaturation

The process in which a protein loses its quaternary, tertiary, and secondary structure present in their native state

17

What causes protein denaturation?

Temperature, pH, Electrolyte concentration

18

What is disrupted during denaturation?

Nonconvalent bonds maintaining secondary, tertiary, and quaternary structure

19

Define: Protein Turnover

Balance between protein building and degrading.

20

True or False? All proteins have a finite lifetime with in the cell.

True

21

What reasons would cause a protein to degrade?

Normal turnover/renewal, mechanism of cellular control, cellular adaptation, damaged, misfolded

22

What is the function of the Ubiquitin-proteasome system?

To identify degradation signals on protein to begin the process of degrading a protein

23

What is the first step in the UPS?

Protein is tagged with ubiquitin

24

What enzyme recognizes specific degradation signals on proteins and then adds a chain of ubiquitin?

Ubiquitin ligases

25

What recognizes tag (chain of ubiquitin) and degrades the protein?

Proteasome

26

What are degraded proteins turned back into?

peptides

27

What recognizes tag (chain of ubiquitin) and degrades the protein?

20s cylinder and 19s caps

28

20s cylinder contains ___________

proteases

29

What is the function of the 19s caps?

Recognizes ubiquitin on the protein as a tag for destruction and unfolds protein and feeds it into the chamber

30

Enzymes act as a __________, which lowers _________ ________

Catalysts; activation energy

31

Define Activation Energy

The amount of energy required for a reaction to take place ( to convert the substrate into a transition state)

32

Catalysts convert substrate into product by _______ or _______ _________ bonds.

Making; breaking; covalent

33

What do catalyst do?

speed up the reaction rate that would normally be slow

34

Coenzyme

a small molecule that functions as a transient carrier of a functional group

35

Cofactor

inorganic ion or molecule that is required for enzyme activity

36

Why, if a protein denatures, will it lose its function?

It causes the protein to lose its shape, the ligand will no longer bind properly to the protein and can no longer perform its function.

37

What type of noncovalent bond assist the ligand to get into position?

Hydrophobic interactions.

38

What matters in the function of the protein?

Size, shape, and chemical properties

39

Hydrolases

hydrolytic cleavage reaction

40

Nucleases

break down nucleic acids

41

Proteases

break down proteins

42

Synthases

synthesize molecules in an anabolic rxn

43

Isomerases

rearrange bonds within a single molecule

44

Polymerases

polymerization rxn

45

Kinases

add phosphate groups to molecules

46

Phosphatases

remove phosphate group from molecules

47

Oxido-reductases

catalyze rxns in which one molecule is oxidized and the other reduced

48

ATPases

hydrolyze ATP

49

Ligases

catalyzes condensation rxns in which 2 atoms are joined using ATP or GTP

50

Dehydrogenases

remove pairs of hydrogen atoms

Decks in Pharmacy BSI Class (58):