Chapter 5 Study Guide

Question 1

Glycolysis

Answer 1

Conversion of glucose into 2 molecules of pyruvic acid.

Question 2

Glycogenesis:

Answer 2

Synthesis of glycogen. Occurs mostly in skeletal muscle and the liver.

Question 3

Glycogenolysis:

Answer 3

Hydrolysis (breakdown) of glycogen (polymer) into many glucoses (monomer).

Question 4

Gluconeogenesis:

Answer 4

The production of glucose from noncarbohydrates.

Question 5

Lipogenesis:

Answer 5

The synthesis (production) of lipids (triglycerides) primarily in adipose tissue.

Question 6

Lipolysis:

Answer 6

The hydrolysis of lipids.

Question 7

Ketogenesis:

Answer 7

The formation of ketone bodies when fatty acids are catabolized.

Question 8

Define: metabolism, catabolism, & anabolism

Answer 8

Metabolism is the breaking down of food for energy, and is done in three stages. 1st is Glycolysis 2nd is the Krebs Cycle and the 3rd is electron transport.
Catabolic reactions release energy, usually by the breakdown of larger molecules into smaller ones. These breakdown glucose, fatty acids, and amino acids and serve as the primary source of energy for the synthesis of ATP
Anabolic reactions require the input of energy and include the synthesis of large energy-storage molecules, including glycogen, fat, and protein.

Question 9

Glucose is catabolized in 3 stages. Name these.

Answer 9

In the first, large organic molecules such as proteins, polysaccharides or lipids are digested into their smaller components outside cells. Next, these smaller molecules are taken up by cells and converted to yet smaller molecules, usually acetyl coenzyme A (acetyl-CoA), which releases some energy. Finally, the acetyl group on the CoA is oxidised to water and carbon dioxide in the citric acid cycle and electron transport chain, releasing the energy that is stored by reducing the coenzyme nicotinamide adenine dinucleotide (NAD+) into NADH.

Question 10

What does “glycolysis” mean? Where in the cell does this process occur?

Answer 10

Glycolysis is an exergoinc reation, and the breakdown of glucose for energy begins with a metabolic pathway in the cytoplasm known as glycolysis. Glucose is converted into two molecules of pyruvic acid, both of which contain three carbons, three oxygens, and four hydrogens. Each of these hydrogens are used to reduce a molecule of NAD, by donating two electrons.

This process occurs in the: DEFINE

Question 11

What happens to glucose immediately as it enters a cell?

Answer 11

The first thing a cell does with the glucose when it enters is to prevent it from leaking back out through the cell membrane. The process is called phosphorylation, and it just involves a hexokinase enzyme converting the glucose to glucose 6-phosphate and then converting that into fructose 6-phosphate with the enzyme glucose phosphate isomerase.

Question 12

Glucose could be stored in a cell as a molecule of ____________

Answer 12

Glycogen and stored (aminal starch)

Question 13

In what 2 tissues is this storage most likely to occur?

Answer 13

The liver and cardiac muscule.

Question 14

If glucose-6-P is to be broken down (catabolized), It is 1st converted into___________

Answer 14

Glycogen Pyruvate/Pyruvic acid

Question 15

Be able to summarize the process of glycolysis, including the products from some of the intermediary steps, and the end products as I did on the board.

Answer 15

Enzyme of Hexokinase, which become glucose-phosphate and it forever traps glucose in the cell. End up with two 3 carbo molecules, you split glucose into 2 3 carbon molecules. You will also get ATP and reduceded NADs. Starts off at 6 Carb molecules, breaks off into 2 3 carbon molecules, along the way you get 2 ATP and 2 reduced NADs.

Question 16

How many ATPs were used? How may ATPs did we gain –

Answer 16

4 are used and 2 ATPs are gained.

Question 17

How many reduced NADs did we gain?

Answer 17

2 reducded NADs

__ are gained

Question 18

Why is lactic acid produced some times?

Answer 18

DEFINE

Question 19

Of what benefit is lactic acid production to glycolysis?

Answer 19

The benefit of lactic acid in the production of glycolysis is that, in the liver, it converts to pyruvic acid and thn convert them to glucose 6-phosphate, which is essentially reverse of glycolysis. This can be used for glyogen systhesis or converte to free glucose. This conversions of non-carbohydrates molecules through pyuvisc acid to glousce is called gluconeogeneisis. It also serves as energy during excersie

Question 20

Is lactic acid a carbohydrate? Why?

Answer 20

No, because it is not easily broken down.

Question 21

Be able to describe the over-all process of the “Cori Cycle”.

Answer 21

The Cori Cycle refers to the metabolic pathway in which lactate produced by anaerobic glycolysis in the muscles moves to the liver and is converted to glucose, which then returns to the muscles and is converted back to lactate. Instead of accumulating inside the muscle cells, lactate produced by anaerobic fermentation is taken up by the liver. This initiates the other half of the Cori cycle. In the liver, gluconeogenesis occurs. From an intuitive perspective, gluconeogenesis reverses both glycolysis and fermentation by converting lactate first into pyruvate, and finally back to glucose. The glucose is then supplied to the muscles through the bloodstream.

Question 22

What was the error in Fig. 5.5 that I pointed out to you?

Answer 22

The figure in 5.5/5.6 should have two line/arrows to represent the two pyruvic acids.

Question 23

What does Aerobic mean?

Answer 23

Aerobic respiration requires oxygen in order to generate ATP. Although carbohydrates, fats, and proteins can all be processed and consumed as reactants, it is the preferred method of pyruvate breakdown in glycolysis and requires that pyruvate enter the mitochondrion in order to be fully oxidized by the Krebs cycle. The product of this process is energy in the form of ATP (adenosine triphosphate), by substrate-level phosphorylation, NADH and FADH2

Question 24

What organelle does the 3-carbon, pyruvic acid enter?

Answer 24

A Mitochondria

Question 25

What happens during what I call the “Pre-Krebs”?

Answer 25

4 NADs is one in the “Pre-Krebs”. The 3-C pyruvic acid enters into the mitochondria that strips off one of the crabs, and then we are left with a two carbon molecule. It also pulls off H and reduces NADH, H. It takes co-enzyme a CoA and we end up with Acetyl CoA (C2) Acetly always = 2 C. Always 2 that enter.

Question 26

Acetyl-CoA binds to what other molecule at the start of the Krebs Cycle?

Answer 26

Oxloacetic Acid, this turns into citric acid.

Question 27

What are the other 2 names for the Krebs Cycle?

Answer 27

Citric Acid Cycle or tricarboxylic acid cycle (TCA Cycle)

Question 28

Be able to summarize what happens during the cycle and what we get out of it.

Answer 28

Acytel-CoA (C2) binds to Oxolacetic Acid (C4), which is turned into Citric Acid(C6). Water is Added and makes cis-Acontic Acid (C6), more water is added and we end up with Isocitric Acid (C6). Then H is removed and a NADH is produced, then CO2 is removed and Ketolgutaric Acid (C5) is created. More CO2 is removed and then 2 more H which produced another NADH. A phosphate is added as well as water, the GTP is and ATP is created as well as Succinic Acid (C4). Then 2 more H are removed which results in the creation of a FADH, H and Fumaric Acid (C6). Then water is added and Malic acid is made (C4). Two Hydrogens are removed making Oxaloacetic Acid and the cycle starts over.

All three C’s of PAcid were oxidized and pulled off as CO2. We get 4 reduced nads, 1 reduced FAD, 1 ATP (indirectly) and 3 CO2 for each P. Acid.

Question 29

Be able to summarize what happens during “Electron Transport and Oxidative Phosphorylation”. FIG 5.10

Answer 29

Oxizide NAD and FAD, to generate ATP. 3 ATP for every reduced NAD and 2 ATP for every reduced FAD.

Question 30

What is the “Final Electron Acceptor”? What is the “End Product” in Electron Transport?

Answer 30

Oxygen is the final Electron Acceptor. We get water, water is the end product of metabolism

Question 31

How many ATPs result from the oxidation of one reduced NAD? Form reduced FAD?

Answer 31

Every reduced NAD there is energy to phosphorlate 3 ATP and for every reduced FAD there is enough energy to phosphorlate 2 ATP.

Question 32

How many ATPs do we get when one molecule of glucose is completely oxidized?

Answer 32

One molecule of glucose yields 38 ATP, 8 produced by glycolsis, 6 from the Krebs cycle. The net gain is 36 ATP, as two of the ATP molecules produced from glycolysis are used in re-oxidation of hydrogen carrier molecule NAD.

Question 33

What are “Free radicals” and “Antioxidants”?

Answer 33

Free Radicals: are molecules with unpaired electrons, in contrast to molecules that are not free radicals because they have two electrons per orbital.
Antioxidants: are molecules that scavenge free radicals and protect the body from reactive oxygen species.

Question 34

What is the name of the process by which the ATPs are actually generated within the mitochrondia? (Fig. 5.11)

Answer 34

Chemiosmotic Theory is the process by which ATP is made/generated within the mito.

Question 35

write the over-all equation involving the oxidation of glucose.

Answer 35

Fig 5.10 in book

Question 36

Understand the process of “Beta-Oxidation”. What are its main products?

Answer 36

Oxygen is added to the beta carbon, the alpha carbon is removed which creates COOH. This continues until there is only tryglyceral left.

Question 37

What happens to these products?

Answer 37

DEFINE

Question 38

What are “Ketone Bodies”? Where do they come from?

Answer 38

DEFINE

Question 39

What are the 3 steps in the catabolism of a polypeptide as I outlined on the board?

Answer 39

DEFINE

Question 40

What happens to the amino group? What does it become?

Answer 40

DEFINE

Question 41

Define: “Essential Amino Acids”? How many are there? Why are they “Essential”?

Answer 41

Amino acids that cannot be produced by the body and must be obtained by the body. They are essential because the body needs time in order to assist all 20 amino acids to build proteins for growth and replace the proteins that are tunred over.

There are 8 that cannot be produced by the body: lysine, tryptophan, phenylalanine, theronine, valine, methionie, leucine, Isoleucine, and (in children) histidine.

Question 42

What does “Transamination” mean? What is its significance?

Answer 42

The transfer of an amino group from an amino acid to an alpha-keto acid, forming a new keto acid and a new amino acid without the appearance of free ammonia. This is important because it is how the body makes amino acid.

Question 43

What is the preferred energy source for the: Brain? Resting Skeletal Muscle? Table 5.4

Answer 43

Brain – Glucose
Resting Skeletal Muscels – Fatty acids
Liver – Fatty Acids
Heart – Fatty Acids

Question 44

What does the term “glucose sparing” mean? What is its significance?

Answer 44

Saving of glucose for the brain, this is important because the brain only runs on glucose.

Question 45

What is the “Key” molecule for most of the metabolic pathways? (Fig 5.17)

Answer 45

Define