Biology *1080 Lecture 18

Question 1

What is energy defined as?

Answer 1

The capacity to do work

Question 2

What is ATP?

Answer 2

Adenosine Triphosphate, the energy currency of the cell

Question 3

What do glucose and fatty acids metabolize?

Answer 3

Most of the ATP

Question 4

Where is some ATP generated by?

Answer 4

Glycolysis and Kreb’s Cycle

Question 5

What does glycolysis, beta oxidation and Kreb’s cycle produce?

Answer 5

Reducing Equivalents (NADH and FADH2)

Question 6

What do NADH and FADH2 supply?

Answer 6

Protons and Electrons to the Electron Transport Chain

Question 7

Where is most ATP generated in?

Answer 7

ETC

Question 8

How can ATP be generated without oxygen?

Answer 8

Phosphocreatine degradation

Question 9

What is the end product in Anaerobic Glycolysis?

Answer 9

Lactate

Question 10

Fat Energy Storage?

Answer 10

Stored as triglycerides in our adipocytes

Question 11

Carbs Energy Storage?

Answer 11

Glycogen in liver

Glycogen in Muscle

Question 12

Protein Energy Storage?

Answer 12

A large potential energy source

Protected but will be used in starvation or caloric restriction

Question 13

Pros of using Carbs as Fuel

Answer 13

• Aerobically it can generate ATP slightly faster than from fat
• Can generate ATP anaerobically

Question 14

Cons of using Carbs as Fuel

Answer 14

Holds a lot of water (heavier), less energy dense then fat

Question 15

Pros of using fat as fuel

Answer 15

Doesn’t hold water, more then twice as energy dense of carbohydrates

Question 16

Cons of using fat as fuel

Answer 16

Can’t provide energy anaerobically (must have oxygen)

Question 17

What is your absorptive state?

Answer 17

The first 3-4 hours after a meal where macronutrients are stored (anabolism)

Question 18

What happens to excess calories in the form of glucose or amino acids?

Answer 18

Gets converted to fat

Question 19

What is your post absorptive state?

Answer 19

Fasting, stored macronutrients are mobilized for energy (catabolism)

Glucose is spared for nervous system

Question 20

What is gluconeogenesis?

Answer 20

Making glucose from non-carbohydrate precursors (occurs in liver - but also kidneys)

Question 21

What is normal fasting blood glucose?

Answer 21

4 - 5.5 mol/L

Question 22

Fasting Hyperglycemia

Answer 22

Glucose > 7mmol/L

Question 23

Fasting Hypoglycemia

Answer 23

Glucose is about , 3.5mmol/L

Question 24

Why is blood glucose maintained so tightly?

Answer 24

• Many cells require glucose
• Maintain osmotic balance
• Hyperglycemia can cause glycosylation of amino acids in kidneys, peripheral nerves, and lens of the eye causing damage

Question 25

Glucose Regulation via Insulin

Answer 25

Beta cells in pancreas secrete insulin, typically after a meal

Question 26

Glucose Regulation via Glucagon

Answer 26

Alpha cells secrete glucagon, induced by fasting

Question 27

What does lower-intensity exercise rely more on?

Answer 27

Plasma-derived substrates, particularly free fatty acids but also some blood glucose

Question 28

What happens when you increase exercise intensity?

Answer 28

Increased need to mobilize energy stores (substrates) within the muscle (glycogen and triglycerides)

Question 29

What is the predominant fuel used during high intensity exercise?

Answer 29

Muscle glycogen

Question 30

What is the major contributing fuel during low intensity exercise (i.e, walking)

Answer 30

Mainly Blood glucose and some fatty acids; some muscle triglycerides and glycogen

Question 31

What is the major contributing fuel during moderate to high intensity (i.e, cycling, running)

Answer 31

Muscle glycogen and triglycerides

Question 32

What is the major contributing fuel during high intensity (i.e, sprinting, weightlifting)

Answer 32

Muscle glycogen, phosphocreatine (PCr)