Chapter 5: Enzymes

Question 1

What proteins speed reactions up?

Answer 1

enzymes

Question 2

In competitive inhibition where do the substrate and inhibitor bind

Answer 2

same site, active site; Vmax stays the same

Question 3

In noncompetitive inhibition where do the inhibitors bind?

Answer 3

allosteric site (different site); may cause a change in active site and therefore, substrate cannot bind so Vmax decreases

Question 4

Why do we prefer competitive inhibitors to non-competitive inhibitors?

Answer 4

They are reversible.

Question 5

Wen you give electrons away it is called ____

Answer 5

oxidation

Question 6

When you accept electrons it is called

Answer 6

reduction (OIL RIG) oxidation is loss, reduction is gain

Question 7

What is oxidative phosphorylation?

Answer 7

When NADH, FADH2, and electrons are made into ATP (energy)

Question 8

Where does the NADH come from in the oxidative phosphorylation?

Answer 8

from pyruvate dehydrogenase, and 3 enzymes in citrate cycle : isocitrate dehydrogenase, alpha-ketoglucarate dehydrogenase, and malate dehydrogenase

Question 9

Where does FADH2 come from in oxidative phosphorylation?

Answer 9

succinate dehydrogenase

Question 10

What coenzyme is needed at the II of ETC?

Answer 10

coenzyme Q

Question 11

What is an electron carrier from III to IV in ETC?

Answer 11

cytochrome C

Question 12

What is a coenzyme of Complex IV?

Answer 12

Copper

Question 13

What occurs at Complex V?

Answer 13

phosphorylation (ADP—ATP)

Question 14

What common drug for cholesterol destroys Coenzyme Q and Cytochrome C?

Answer 14

statins

Question 15

What drug can block Complex 1?

Answer 15

Rotenone (pesticide)

Question 16

What drug can block Complex IV?

Answer 16

CO, CN, Chloramphenicol

Question 17

Why will the Hb saturation be normal in carbon monoxide poisoning?

Answer 17

Because CO is a competitive inhibitor of O2; that is why to overcome CO we must give 100% O2 (increase substrate, up Km).

Question 18

What kinds of bacteria does chloramphenicol cover? Why don’t we like to use it?

Answer 18

all gram +, simple gram -, rickettsia; affects all rapidly dividing cells by blocking the 50s subunit and its peptidyl transferase; causes aplastic anemia and gray baby syndrome

Question 19

Compounds that grab protons in ETC and drag them back into the matrix and stops ATP synthesis, releasing a lot of energy are called __________.

Answer 19

uncouplers

Question 20

Examples of uncouplers

Answer 20

aspirin, succinylcholine (malignant hyperthermia), haloperidol (neuroleptic malignant syndrome), DNP (dinitrophenol) pesticide, free fatty acids

Question 21

Tx for malignant hyperthermia and neuroleptic malignant syndrome?

Answer 21

dantrolene: stabilizes sarcoreticular and ryandine arm so no Ca for contraction

Question 22

What does uncoupling do to the liver?

Answer 22

shrinks it

Question 23

What conditions cause microsteatosis of liver?

Answer 23

pregnancy, tylenol poisoning, Reye’s syndrome

Question 24

What conditions cause macrosteatosis of liver?

Answer 24

obesity (NAFLD); and alcohol

Question 25

What kind of enzyme phosphorylates a stubstrate using ATP?

Answer 25

kinase

Question 26

What is a cofactor for kinase?

Answer 26

magnesium

Question 27

What kind of enzyme phosphorylates a substrate using free phosphate?

Answer 27

phosphorylase

Question 28

What kind of enzyme creates an isomer from a substrate?

Answer 28

isomerase

Question 29

What has the same chemical makeup and structure but differ around one chiral carbon?

Answer 29

epimer

Question 30

What kind of enzyme makes epimers?

Answer 30

epimerase

Question 31

What kind of enzyme moves a side chain from one carbon to another carbon?

Answer 31

mutase

Question 32

What kind of enzyme transfers a side chain from one substrate to another?

Answer 32

transferase

Question 33

What kind of enzyme transfers amino acids from or onto amino acids?

Answer 33

transaminase

Question 34

What kind of enzyme cuts carbon-carbon bonds and must use ATP to do it?

Answer 34

lyase

Question 35

What kind of enzyme uses carbon dioxide to create a carbon-carbon bond but uses biotin as a cofactor?

Answer 35

carboxylase

Question 36

What kind of enzyme is used to stack substrates together to create a product?

Answer 36

synthase

Question 37

What kind of enzyme uses ATP to stack substrates together to create a new product?

Answer 37

synthetase

Question 38

What kind of enzyme uses a cofactor to take hydrogens off substrates?

Answer 38

dehydrogenase

Question 39

What kind of enzyme uses water to break bonds?

Answer 39

hydrolase

Question 40

When a sulfur bond is broken in the reaction, what word do we add in front of enzyme name?

Answer 40

Thio--