Lectures 39 & 40

Question 1

How can ketoacidosis cause lactic acidosis?

Answer 1

Acidosis can block binding of oxygen to hemoglobin and hemoglobin to tissues.

Question 2

During high intensity exercise, what are your muscles using for energy?

Answer 2

Glycogen and blood glucose

Question 3

What is happening to epinephrine during exercise?

Answer 3

It is increased

Question 4

What is happening to insulin during exercise?

Answer 4

it is decreased

Question 5

What is happening to glucagon during exercise?

Answer 5

it is increased

Question 6

What is regulating glycogen breakdown in the muscle tissue during high intensity exercise?

Answer 6

Epinephrine, AMP

Question 7

When insulin is decreasing, how is glucose uptake increasing in the skeletal muscle during exercise?

Answer 7

Skeletal muscle has two pools of glut transporters. One is regulated by insulin and the other one responds to contraction (doesn’t respond to insulin).

Question 8

What is the definition of a free radical?

Answer 8

a molecule with an unpaired electron

Question 9

How do ROS/RNS damage macromolecules?

Answer 9

The can attach to macromolecules, they can also act as an oxidizing agent or a reducing agent

Question 10

How are most of the ROS/RNS produced in the body?

Answer 10

In the mitochondria of most cells via the ETC

Question 11

What is the function of superoxide dismutase?

Answer 11

Converts O2.- (superoxide) to H2O2

Question 12

What are free radicals also called?

Answer 12

ROS or RNS

Question 13

A free radical is always an ROS/RNS, but is an ROS/RNS always a free radical?

Answer 13

No

Question 14

What are two examples of ROS/RNS that are reactive and damaging to the cell but are not technically free radicals because they do NOT have an unpaired electron?

Answer 14

Hydrogen peroxide (H2O2)
Peroxynitrite (ONOO-)

Question 15

What do ROS/RNS do? (2 things)

Answer 15

Act as signaling molecules and damage other molecules

Question 16

How are ROS/RNS produced?

Answer 16

In the mitochondria during aerobic respiration

Question 17

Where is nitric oxide and peroxynitrite produced?

Answer 17

in the mitochondria

Question 18

Nitric oxide is produced via ______ ____________ _________.

Answer 18

Nitric Oxide synthase (NOS)

Question 19

Nitric oxide and superoxide can react to form what?

Answer 19

peroxynitrite

Question 20

What can WBC produce?

Answer 20

superoxide, hydrogen peroxide, hydroxyl radical, & hypochlorous acid (aka bleach)

Question 21

What is the function of ROS?

Answer 21

kill bacteria and viruses, but they can leak out of the WBC and damage surrounding healthy tissue

Question 22

Name 5 environmental/external sources which can stimulate ROS/RNS production in cells?

Answer 22

UV light, ionizing radiation, smoking, air pollution, medications

Question 23

What are the 2 medications that were discussed that can stimulate ROS/RNS production in cells?

Answer 23

acetaminophen and doxorubicin

Question 24

How do cells protect against ROS/RNS?

Answer 24

antioxidants

Question 25

What is an antioxidant?

Answer 25

scavenger of ROS/RNS & when it is present in small amounts will inhibit the oxidation of the bulk

Question 26

What are the 3 enzymatic antioxidants?

Answer 26

superoxide dismutase, catalase, & glutathione peroxidase (GPX)

Question 27

What are the 3 non-enzymatic antioxidants?

Answer 27

Glutathione (GSH), Coenzyme Q, Alpha-lipoic acid

Question 28

What is glutathione and what does it consist of?

Answer 28

It is a tripeptide (cyteine, glutamate, glycine)

Question 29

What does glutathione act as?

Answer 29

an electron donor to neutralize free radicals

Question 30

What catalyzes the reactions where GSH is conjugated to chemicals to neutralize them?

Answer 30

glutathione-s-transferase

Question 31

What ratio is often used to assess the level of oxidative stress in the cell?

Answer 31

GSH/GSSG

Question 32

Is Coenzyme Q synthesized by the body?

Answer 32

yes

Question 33

Is alpha-lipoic acid synthesized by the body?

Answer 33

yes

Question 34

What are 3 characteristics of alpha-lipoic acid?

Answer 34

1. water & lipid soluble 2. can protect against free radicals in all parts of the cell 3. enhance the function of vitamin C and E

Question 35

What are 4 antioxidants that were discussed that are NOT synthesized by the body?

Answer 35

vitamin C, vitamin E, N-acetylcysteine (NAC), flavonoids

Question 36

What is vitamin C soluble in?

Answer 36

water

Question 37

What is vitamin E soluble in?

Answer 37

lipids

Question 38

What does vitamin E protect against?

Answer 38

free radical damage in membranes

Question 39

NAC acts a donor of what?

Answer 39

donor of cysteine for GSH biosynthesis

Question 40

What is oxidative stress?

Answer 40

term used to describe an imbalance between ROS/RNS production and antioxidant status

Question 41

What is the net result of oxidative stress?

Answer 41

oxidative damage to macromolecules

Question 42

What are the 3 ways that ROS/RNS can cause or contribute to disease progression?

Answer 42

1. damage DNA 2. damage proteins (oxidation or nitration) 3. damage lipids (lipid peroxidation)