Exam 2: Chapter 9, Energy Metabolism

Question 1

Pathways that build compounds

Answer 1

anabolic

Question 2

pathways that break down compounds

Answer 2

catabolic

Question 3

What is the difference between metabolism, catabolism, and anabolism?

Answer 3

Metabolism can be described as a summation of both anabolism and catabolism.

• Metabolic Pathway
  
  • A group of biochemical reactions that occur in progression from beginning to end

Question 4

1. Adenosine triphosphate (ATP): Body’s source of…
2. Adenosine diphosphate (ADP): What results from…
3. Adenosine monophosphate (AMP): Results from hydrolysis…

Answer 4

1. Body’s source of energy derived from catabolic reactions of macronutrients
2. What results from cells’ breakdown of a high phosphate bond in ATP
3. Results from hydrolysis of ADP when ATP levels in cell are low

Question 5

Stages of Catabolism

Answer 5

Question 6

Structure of ATP

Answer 6

Question 7

ATP synthesis depends on transfer of electrons in a series of reactions from energy-yielding compounds to oxygen

• Oxidation-reduction reactions occur together
  
  • Oxidized substance:
  • Reduced substance:
• Role of coenzymes NAD+ and FAD+

Answer 7

Oxidized substance: Loses electron(s); gains oxygen/loses hydrogen

Reduced substance: Gains electron(s); loses oxygen/gains hydrogen

Question 8

Oxidizes food molecules to obtain energy

Answer 8

Cellular respiration

Question 9

Net gain 30-32 ATP

Answer 9

Aerobic respiration of one glucose molecule

Question 10

Net gain 2 ATP

Answer 10

Anaerobic respiration of one glucose molecule

Question 11

Steps of Aerobic cellular respiration of glucose:

1.Glycolysis: Glucose is…

2.Transition reaction: Pyruvate is…

3.Citric Acid Cycle (CAC): Acetyl-CoA enters…

4.Electron Transport Chain: NADH+, H+, FADH2 are…

Answer 11

1. Glycolysis: Glucose is oxidized to pyruvate, producing NADH +H+
2. Transition Reaction: Pyruvate is oxidized and joined with CoA, producing acetyl-CoA and NADH +H+
3. Citric Acid Cycle (CAC): Acetyl-CoA enters cycle producing NADH +H+, FADH2 and ATP; CO2 also produced
4. Electron Transport Chain: NADH + H+, FADH2 are oxidized to NAD+ and FAD

Question 12

Electron Transport Chain:

• Passage of electrons along a series of electron carriers
• Process called ; how energy is derived from NADH + H+ and FADH2
• Minerals involved:

Answer 12

1. oxidative phosphorylation
   
   • Copper: component of an enzyme
   • Iron: component of cytochromes

Question 13

Anaerobic Metabolism:

• Occurs in cells with no mitochondria or in all cells when there is no oxygen
• • *

Answer 13

1. Pyruvate is converted to lactate
2. Lactate is picked up by the liver
3. Liver synthesizes compounds used in aerobic metabolism from lactate

Question 14

ATP production from fats:

Lipolysis

• Tryglycerides broken down into

Answer 14

Triglycerides broken down into fatty acids and glycerol

Question 15

ATP production from fats:

Fatty Acid Oxidation (beta-oxidation):

• takes place in the
• shuttles fatty acids from cytosol into mitochondria
• Promoted by , , and
• Yields , and , resulting in about ATP

Answer 15

• Takes place in mitochondria
• Carnitine shuttles fatty acids from cytosol into mitochondria
• Promoted by glucagon, growth hormone, epinephrine
• Yields acetyl-CoA and NADH + H+ resulting in about 106 ATP

Question 16

Where does ATP production of fats occur?

Answer 16

Question 17

Alternate Fat Metabolism: Ketogenesis

• Carbohydrates aid fat metabolism

1. Ketogenesis:
2. Ketosis:

Answer 17

1. Ketogenesis: Ketone bodies formed by incomplete fatty acid oxidation
2. Ketosis:
   
   1. ​in Type 1 Diabetes
   2. in Semistarvation or Fasting

Question 18

Protein metabolism:

• Deamination
  
  • Loss of:
  • Requires:
  • Carbon skeleton:

Answer 18

• Loss of the amino group from and amino acid
• Requires Vitamin B-6
• Carbon skeleton is left to enter CAC

Question 19

Protein metabolism:

• Glucogenic Amino Acids
  
  • Can form:

Answer 19

Can form pyruvate and become glucose

Question 20

Protein metabolism:

• Ketogenic Amino Acids
  
  • Forms…

Answer 20

Forms acetyl CoA and cannot become glucose

Question 21

Protein Metabolism:

• Gluconeogenesis
  
  • Forming glucose from…
  • Typical fatty acids cannot…

Answer 21

• Forming glucose from glucogenic amino acids (e.g. alanine) and other compounds
• Typical fatty acids cannot be converted to glucose, although glycerol can

Question 22

Protein Metabolism:

• Disposal of Excess Amino Groups:
  
  • Converted to…
  • Urea exreted…

Answer 22

• Converted to ammonia; then urea cycle
• Urea excreted in the urine

Question 23

Alcohol Metabolism:

• ADH Pathway
  
  • where does it occur?
  • alcohol converted…
  • acetaldehyde converted to…

Answer 23

• 10-30% in stomach and the rest in liver
• Alcohol converted to acetaldehyde
• Acetaldehyde converted to acetyl-CoA, producing NADH + H+

Question 24

Alcohol Metabolism:

• MEOS:
  
  • moderate to…
  • uses…

Answer 24

• Moderate to excessive alcohol
• Uses energy rather than producing energy

Question 25

Regulation of energy metabolism: 1. 2. 3.

Answer 25

1. **Liver** 1. Nutrient interconversions and storage 2. **ATP Concentrations regulate metabolism** 1. High ATP promote anabolic reactions 2. High ADP stimulate catabolic reactions 3. **Enzymes, Hormones, Vitamins and Minerals**

Question 26

What happens where: Glycolysis (glucose → pyruvate)

Answer 26

cytosol

Question 27

What happens where: Transition reaction (pyruvate → acetyl-CoA)

Answer 27

mitochondria

Question 28

What happens where: Citric acid cycle (acetyl-CoA → CO₂)

Answer 28

Mitochondria

Question 29

What happens where: Gluconeogenesis

Answer 29

Begins in the mitochondria, then moves to the cytosol

Question 30

What happens where: Beta oxidation (fatty acid → acetyl-coA)

Answer 30

Mitochondria

Question 31

What happens where: Glucogenic amino acid oxidation (amino acids → pyruvate)

Answer 31

Cytosol

Question 32

What happens where: Non-glucogenic amino acid oxidation (amino acids → acetyl-CoA)

Answer 32

Mitochondria

Question 33

What happens where: Alcohol oxidation (ethanol → acetylaldehyde) (acetylaldehyde → acetyl-CoA)

Answer 33

cytosol mitochondria

Question 34

Just *kinda* know this chart...

Question 35

Fasting encourages:

Answer 35

* Glycogen breakdown * Body fat and protein breakdown * Gluconeogenesis * Ketogenesis * Urea synthesis

Question 36

Feasting encourages:

Answer 36

* Glycogen synthesis * Body fat synthesis (lipogenesis) * Protein synthesis

Question 37

Question 38

Inborn errors of metabolism

Answer 38

* Newborn screening * Phenylketonuria (PKU) * Unable to metabolize phenylalanine * Galactosemia * Unable to metabolize galactose * Glycogen Storage Disease * Inability to convert glycogen to glucose