Chapter 03 Energy Transfer

Question 1

What are the laws of thermodynamics and why do they matter with nutrition?

Answer 1

Principles that govern energy exchange.
Converting energy in food for metabolism.

Energy transfer

Question 2

For our regular functioning, what role do “new” nutrients play? What role do “stored” nutrients play?

Answer 2

Stored nutrients provide bulk of daily functions

Body will us new nutrients during longer duration exercise.

Question 3

What are the two most important nutrient/energy stores in the human body? How are they responsible for survival?

Answer 3

Triglycerides stored in fat and muscle cells

Glycogen stored in muscle and liver

Also provide for brain and RBC.

Question 4

Why are the bonds contained in ATP so important?

Answer 4

Energy is release when the carbon-hydrogen bonds of our carbs, fats and protein are broken, as well as when these adenosine-phosphate bonds are broken.

Question 5

What is the body’s “simple priority” when it comes to forming ATP?

Answer 5

to break the carbon-hydrogen bonds in carbs, fats and proteins and to use the energy release to regenerate adenosine-phosphate bonds forming ATP.

Question 6

What are the three energy regeneration pathways? Provide the two main points for each?

Answer 6

ATP-PCr
first system to kick in, uses enzyme creatine kanse to brek bonds between creatine and phosphate that are joined in a phosphocreatine molecule.This energy helps to regenerate ATP. Can only give energy for about 10 sec.

Glycolytic pathway
after that, in cell cytosol breaks down stored muscle glycogen, blood glucose and glycerol from triglycerides to help regenerate ATP. if process is running quickly, will produce pyruvate and NADH. Pyruvate becomes lactic acid. lasts for about 80 seconds.

Oxidative phosphorylative pathway
can only sustain low level of intensity, two processes, Krebs cycle and electron transport chain. pyruvate converted into acetyl-CoA is funneled into the Krebs Cycle. takes place in the mitochondrion, makes one molecule of ATP, two CO2, and releasing 8 hydrogen ions every turn of the wheel.
electron transport chain - hydrogen protons rush into mitochondria chamber and produce 32 molecules of ATP.

all three systems - one molecule of glucose into 36 of ATP.

Question 7

What are NAD+ and FAD? What do they do in the body? What nutrients are necessary to form them?

Answer 7

NAD+, grabs hydrogens, with pyruvate to create lactic acid allows us to continue to exercise, also part of electron transport chain.

FAD binds hydrogen for electron transport chain.

derived from vitamins B3 (niacin) and B2 (roboflavin)

Question 8

What are the five major carbohydrate metabolic pathways? Describe the main purpose of each.

Answer 8

1. glycogenesis - synthesis of glycogen
   adding glucose molecules to a chain of glucose called glycogen
2. glycogenolysis - breakdown of stored glycogen to glucose
   either to create ATP or just glucose for other cells
   happens during high energy demand
3. glycolysis - series of rx in the cytosol that converts glucose into pyruvic acid and ultimately ATP.
4. Krebs cycle and electron transport chain
5. gluconeogenesis - conversion of non-carb compounds
   liver can make glucose from non-carbs.

Question 9

What is the purpose of fatty acids and triglycerides in the body?

Answer 9

1. provide the structure of our plasma membranes;
2. help regulate hormone function;
3. help transport certain vitamins and minerals in the body;
4. act as the largest fuel depot in the body.

Question 10

Briefly describe lipolysis?

Answer 10

breakdown of triglycerides into fatty acids and glycerol.
Glycerol can enter the glycolytic pathway for energy
process carried out by hormone sensitive lipase (enzyme)

Question 11

Briefly describe beta-oxidation.

Answer 11

when fatty acids needed for energy then run through beta-oxidation
breaks fatty acids into acetyl-CoA for Krebs cycle and transport chain.
generates more ATP than glycolysis
process is aerobic

Question 12

What are ketones? Why would they be formed?

Answer 12

liver create ketone bodies with carbs and oxaloacetate are low.
acetyl-CoA builds up (needs oxaloacetate for Krebs cycle) and shifts liver into ketone body formation.
can be reconverted into acetyl-CoA in brain, RBC, muscle

Question 13

What needs to happen for fatty acid synthesis to occur?

Answer 13

mostly takes place in liver but can in adipose tissue.
occurs when energy demands are low, dietary excess, high insulin
- high sugar diet
excess acetyl-CoA join together to form new fats

Question 14

What is cholesterol? What functions does it have in the body?

Answer 14

roles

1. in cell membrane function;
2. in the absorption of dietary fat;
3. in the synthesis of steroid hormones (including vitamin D);
4. in the synthesis of bile salts.

2/3 of all cholesterol is made in the liver, made from acetyl-CoA

Question 15

What is the role of HDL and LDL in the body?

Answer 15

LDL - primarily responsible for delivering cholesterol and tryglycerides to our cells for use in membrane construction, conversion into hormones, and storage. (also deposits in peripheral tissues.

HDL - carrying cholesterol from cells and other lipoproteins to the liver where it can be excreted in the bile.

Question 16

Describe the purpose of the amino acid pool and what it contains.

Answer 16

after protein is broken down, after absorption and clearance through the liver, these amino acids enter the bloodstream.

can be used in the productions of enzymes, hormones, neurotransmitters, antibodies, transport proteins, muscle proteins

can be used to create glucose,fatty acids,cholesteral, ketone

need adequate protein intake to maintain this pool

Question 17

What are the two major categories of amino acids? What three eventual fates do amino acids have in the body?

Answer 17

body can make 12 non-essential amino acids
8 essential amino acids must come from diet

three fates

1. can be joined together to create new proteins;
2. can be catabolized to form non-protein compounds
3. can be catabolized in order to transfer energy

Question 18

Why would gluconeogenesis occur?

Answer 18

when liver glycogen stores are low then gluconeogensis

Question 19

What are BCAAs? What is their purpose during exercise?

Answer 19

can be catabolized in the muscle for energy transfer

during longer exercise can provide 5% of total energy requirement

Question 20

When would something be “delaminates?”

Answer 20

when amino acids are needed to from non-protein compounds or to transfer energy to ATP, these nitrogen groups must be eliminated. process is called deaminiation.

carbon skeleton after deamination can be converted to glucose, ketone bodies, cholesterol, fatty acids or a compound for the Krebs cycle

Question 21

What is the purpose of protein turnover and how is it regulated?

Answer 21

cellular proteins are continually recycled.

governed by protein synthesis and protein breakdown
regulated by nutritional intake, exercise habits, health status and illness, stress, hormonal status and genetic programming