Chapter 9 - Energy Metabolism

Question 1

Metabolism

Answer 1

Chemical processes in the body that provide energy in useful forms and sustain vital activities

Question 2

Metabolic Pathway

Answer 2

Series of chemical reactions occurring in a cell

Question 3

Intermediate

Answer 3

Compound formed in a metabolic pathway

Question 4

Anabolic

Answer 4

Pathways that use small, simple compounds to build larger, more complex compounds.
ex: glucose, fatty acids, cholesterol, amino acids

Question 5

Catabolic

Answer 5

Pathways that break down large compounds into smaller compounds. Energy is usually released.
ex: glycogen

Question 6

Cells use energy to…

Answer 6

• build compounds
• contract muscles
• conduct nerve pulses
• pump ions

Question 7

How do catabolic processes release energy?

Answer 7

By breaking the chemical bonds in carbs, fats, proteins, and alcohol

Question 8

Adenosine Triphosphate (ATP)

Answer 8

Main energy currency for cells. ATP energy is used to promote ion pumping, enzyme activity, and muscular contraction.

Question 9

Adenosine Diphosphate (ADP)

Answer 9

Breakdown product of ATP. ADP is synthesized into ATP using energy from foods and a phosphate group (P1)

Question 10

Adenosine Monophosphate (AMP)

Answer 10

Breakdown product of ADP when a phosphate group is removed. AMP is produced when ATP is in short supply.

Question 11

How many pounds of ATP does the body contain at any given time?

Answer 11

0.22 lbs

Question 12

How many pounds of ATP does a sedentary adult use every day?

Answer 12

~ 88 lbs

Question 13

How much ATP is used during an hour of strenuous exercise?

Answer 13

66 lbs

Question 14

Oxidize means to _____ an electron, while reduced means to _____ an electron

Answer 14

lose ; gain

Question 15

What removes hydrogen from energy-yielding compounds or their breakdown products?

Answer 15

Dehydrogenases

Question 16

Coenzyme

Answer 16

Compound that combines with an active protein (apoenzyme) to form a catalytically active protein (holoenzyme). In this manner, coenzymes aid in enzyme function.
ex: niacin, riboflavin

Question 17

Cellular Respiration

Answer 17

Oxidation (electron removal) of food molecules resulting in the eventual release of energy, CO2, and water.

Question 18

Aerobic

Answer 18

Requiring oxygen.

More efficient at producing ATP.

Question 19

Anaerobic

Answer 19

Not requiring oxygen.

Question 20

Cytosol

Answer 20

Water-based phase of a cell’s cytoplasm; excludes organelles, such as mitochondria

Question 21

What are the 4 stages of aerobic cellular respiration?

Answer 21

1. Glycolysis
2. Transition Reaction
3. Citric Acid Cycle
4. Electron Transport Chain

Question 22

Stage 1 of Aerobic Cellular Respiration: Glycolysis

Answer 22

Glucose is oxidized and forms 2 molecules of the 3 carbon compounds pyruvate, produces NADH + H+, and generates a net of 2 molecules of ATP.
- Occurs in cytosol

Question 23

Stage 2 of Aerobic Cellular Respiration: Transition Reaction

Answer 23

Pyruvate is further oxidized and joined with conezyme A (CoA) to form acetyl-CoA.
Produces NADH + H+ and releases CO2 as a waste product.
- Occurs in mitochondria

Question 24

Stage 3 of Aerobic Cellular Respiration: Citric Acid Cycle (or Krebs Cycle, Tricarboxylic Acid Cycle (TCA Cycle))

Answer 24

Acetyl-CoA enters the citric acid cycle, resulting iin the production of NADH + H+, FADH2, and ATP.
CO2 is released as a waste product.
- Occurs in mitochondria

Question 25

Stage 4 of Aerobic Cellular Respiration: Electron Transport Chain

Answer 25

The NADH + H+ produced in stages 1 - 3 and FADH2 from stage 3 enter the electron transport chain. The NADH + H+ is oxidized to NAD+. and FADH2 is oxidized to FAD. At the end of the electron transport chain, O2 is combined with hydrogen ions (H+) and electrons to form water. Most ATP is produced in the electron transport chain, so the mitochondria are the cell's major energy-producing organelles.

Question 26

Mitochondria

Answer 26

Main sites of energy production in a cell that also contains the pathway for oxidizing fat for fuel, among other metabolic pathways.

Question 27

Roles of Glycolysis

Answer 27

Break down carbs to provide energy and provide building blocks for synthesizing other compounds

Question 28

The transition reaction requires coenzymes from...

Answer 28

thiamin, riboflavin, niacin, and pantothenic acid

Question 29

Oxidative Phosphorylation

Answer 29

Process by which energy dervied from the oxidation of NADH + H+ and FADH2 is transferred to ADP + P1 to form ATP

Question 30

Cytochrome

Answer 30

Electron-transfer compound that participates in the electron transport chain ex: iron

Question 31

Anaerobic Glycolysis

Answer 31

Pyruvate + NADH + H+ ---> Lactate + NAD+

Question 32

What is the only method for making ATP in cells without mitochondria?

Answer 32

Anaerobic glycolysis

Question 33

Lactate is also created during what?

Answer 33

Intensive exercise

Question 34

Lipolysis

Answer 34

Breakdown of triglyercides to glycerol and fatty acids

Question 35

Fatty Acid Oxidation (AKA Beta-Oxidation)

Answer 35

Breakdown of fatty acids into compounds that enter the citric acid cycle. - Occurs in mitochondria

Question 36

Carnitine

Answer 36

Compound used to shuttle fatty acids from the cytosol of the cell to the mitochondria

Question 37

Pyruvate can synthesize ______ for the citric acid cycle.

Answer 37

Oxaloacetate

Question 38

Ketone Bodies

Answer 38

Incomplete breakdown products of fat, containing 3 or 4 carbons. Most contain a chemical group called a ketone. ex: acetoacetic acid

Question 39

Ketosis

Answer 39

Condition of having a higher concentration of ketone bodies and related breakdown products in the bloodstream and tissues. Can lead to diabetic ketoacidosis.

Question 40

Where does metabolism protein take place?

Answer 40

Liver (except amino acids leucine, isoleucine, valine)

Question 41

Glucogenic Amino Acids

Answer 41

Amino acid that can be converted into glucose via gluconeogenesis

Question 42

Ketogenic Amino Acids

Answer 42

Amino acid that can be converted to acetyl-CoA and form ketones

Question 43

Gluconeogenesis

Answer 43

Generation of new glucose from glucogenic amino acids.

Question 44

The catabolism of amino acids creates ________, which must be excreted

Answer 44

ammonia (NH3)

Question 45

What is the main pathway or alcohol metabolism?

Answer 45

Alcohol dehydrogenase (ADH)

Question 46

Alcohol is mainly metabolized in the ______, although 10-30% of it may be metabolized in the _________

Answer 46

liver ; stomach

Question 47

Steatosis

Answer 47

Accumulation of fat in the liver

Question 48

What is a pathway to metabolize excess alcohol?

Answer 48

Micromosal Ethanol Oxidizing System (MEOS)

Question 49

What is a minor pathway for alcohol metabolism?

Answer 49

Catalase pathway

Question 50

The liver is important for what metabolic processes?

Answer 50

- conversions between various forms of simple sugars - fat synthesis - production of ketone bodies - amino acid metabolism - urea production - alcohol metaolism - nutrient storage

Question 51

What vitamins are needed for metabolic pathways to operate? (9)

Answer 51

- B-vitamins - thiamin - riboflavin - niacin - pantothenic acid - biotin - vitamin B-6 - folate - vitamin B-12

Question 52

What minerals are needed for metabolic pathways to operate?

Answer 52

iron, copper

Question 53

When your lean body mass declines by __%, after ___ to ___ weeks of fasting, you will die

Answer 53

50% ; 7 to 10 weeks

Question 54

Lipogenesis

Answer 54

Synthesis of fat from excess carb or protein intake

Question 55

Phenylketonuria (PKU)

Answer 55

Enzyme phenylalanine hydroxylase doesn't function efficiently in the liver to convert phenylalanine into tyrosine

Question 56

Galactosemia

Answer 56

2 specific enzyme defects lead to a reduction in the metabolism of galactose into glucose

Question 57

Glycogen Storage Disease

Answer 57

Liver is unable to convert glycogen to glucose