wk 2 - Gluconeogenesis & General Regulatory Mechanisms COPY

Question 1

In Cori Cycle, lactate is produced in the ———– (organ) and it is converted to ———- (carbohydrate).

Answer 1

In Cori Cycle, lactate is produced in the liver and it is converted to glucose.

Question 2

10?

(pathway)

Answer 2

lipolysis

(triacylglycerols/fatty acids are broken down via beta oxidation to produce acetyl coa molecules & glycerol)

Question 3

Glycerol is mostly found in the adipose tissue (subcutaneous), it goes to the —-where it gets converted to —-, which can be used as a fuel in other tissues.

a) Adipose tissue
b) Muscle
c) Liver
d) Glucose
e) Glycogen

Answer 3

Glycerol is mostly found in the adipose tissue (subcutaneous), it goes to the liver where it gets converted to glucose, which can be used as a fuel in other tissues.

Question 4

Which 3 reactions during glycolysis are irreversible during gluconeogenesis?

a) Step 1, 8 & 10
b) Step 1, 3 & 10
c) Step 1-3
d) Step 8-10

Answer 4

b) Steps 1, 3 & 10

(3 kinases)

S1 - hexokinase requires 2 ATP

S3 - PFK-1 requires 2 ATP

S10 - pyruvate kinase requires 4 ATP

Question 5

The liver itself can’t use the ketone bodies as a source of energy as it lacks the enzyme ____ ________ ___ ________, also called _________, that is responsible for producing acetyl CoA from the ketone bodies.

Answer 5

The liver itself can’t use the ketone bodies as a source of energy as it lacks the enzyme β-ketoacyl-CoA transferase, also called thiophorase, that is responsible for producing acetyl CoA from the ketone bodies.

Question 6

during starvation, in what order are the following molecules utilised as fuel?

• proteins (muscle)
• ketones
• glucose
• fatty acids + minimal proteins
• glycogen

Answer 6

1. Glucose
2. Glycogen
3. Fatty acids + minimal protein
4. Ketones
5. Proteins (muscle)

…then death

Question 7

during starvation, the human body’s first priority is to:

Answer 7

provide sufficient glucose to brain and other tissues that are dependent on it (Figure A)

Question 8

8?

(pathway)

Answer 8

glycolysis - TCA cycle

pyruvate is sent from the cytoplasm into the mitochondria via pyruvate translocase, and is then converted to acetyl CoA via pyruvate deydrogenase complex (PDH) to enter the TCA cycle

Question 9

________ is an important product for the synthesis of ATP and citrate via the Krebs Cycle. It is produced from:

1. fatty acids (during beta oxidation - lipolysis)
2. glucose (end product of glycolysis)
3. amino acids (during Cahill cycle)
4. ketone bodies (precursor for ketogenesis)
5. oxaloacetate (during Gluconeogenesis)
6. and ethanol (via ADH)

Answer 9

Acetyl CoA

Question 10

If acetyl CoA is the precursor for production of energy via TCA cycle, what is the purpose of converting acetyl CoA by the liver mitochondria to ketone bodies, then re-converting ketone bodies to acetyl CoA in the tissues?

Answer 10

ketone bodies are water soluble and can be transported from the liver to other tissues easily without the need of albumin or lipoproteins as carriers.

Question 11

In the human body, which fuel store can last for the longest time?

Answer 11

adipose fat

Question 12

Lymphatic cells absorb and transport fatty acids and lipids as _____ from the digestive system

Answer 12

Lymphatic cells absorb and transport fatty acids and lipids as lymph from the digestive system

Question 13

When _________ stores are depleted, the liver is able to synthesize glucose from lactate, via ___________

Answer 13

When Glycogen stores are depleted, the liver is able to synthesize glucose from lactate, via gluconeogenesis

Question 14

13?

(pathway)

Answer 14

ketogenesis

acetyl CoA is used to make ketone bodies - betahydroxybutyrate & acetoacetate

Question 15

A ketogenic amino acid can be degraded directly into ________, which is the precursor of ketone bodies

Answer 15

A ketogenic amino acid can be degraded directly into acetyl-CoA, which is the precursor of ketone bodies

Question 16

When do muscle cells use the Cahill cycle and not the Cori-cycle?

When the muscles need to get rid of ——-

a) Ammonia
b) Oxaloacetate
c) Water
d) Lactic acid

Answer 16

a) Ammonia

In the Cahill cycle, pyruvate is converted to alanine in muscle cells, then to glucose in the liver when there is a need to transfer ammonia to the liver.

Question 17

Compartmentation is the seperation of ________ and _________ pathways

Answer 17

Compartmentation is the seperation of synthesis and degradation pathways

Question 18

What is the main hormone secreted to reduce the blood glucose level?

a) Glucagon
b) Growth hormone
c) Insulin
d) Oestrogen

Answer 18

c) Insulin

Question 19

Glycolysis produces —– ATP, whereas, gluconeogenesis consumes —- ATP.

Answer 19

Glycolysis produces 2 ATP, whereas, gluconeogenesis consumes 6 ATP.

Question 20

Glycogen is formed from ——, which is glycolysed to —-, then to —–, then getting stored in ——— as glycogen.

a) Adipose tissues and liver
b) Glucose
c) Glucose-1-phosphate
d) Glucose-6-phosphate
e) Muscle and liver

Answer 20

Glycogen is formed from Glucose, which is glycolysed to Glucose-6-phosphate then to Glucose-1-phosphate, then getting stored in Muscle and liver as glycogen.

Question 21

The glycogen stored in muscle is made accessible to be used by other organs.

a) True
b) False

Answer 21

b) False

• Only the glycogen stored in the liver can be made accessible

to other organs.

Question 22

The Cori cycle (lactate to glucose) normally accounts for 20% of glucose turnover, but it was shown to be increased to 50% in ————— patients.

a) Arthritis
b) Cachectic cancer
c) Cirrhosis
d) Diabetic
e) Glucoma

Answer 22

The Cori cycle (lactate to glucose) normally accounts for 20% of glucose turnover, but it was shown to be increased to 50% in Cachectic cancer patients.

(Cachexia is characterized by loss of adipose tissue and skeletal muscle mass - wasting syndrome)

Question 23

ethanol is primarily metabolised by the liver, converted to ___________ by alcohol dehydrogenase (ADH) which takes place in the cytoplasm. This toxic product is then converted to ______ by aldehyde dehydrogenase

(some is metabolised in the stomach - the stomach lining contains ADH)

Answer 23

ethanol is primarily metabolised by the liver, converted to acetaldehyde by alcohol dehydrogenase (ADH) which takes place in the cytoplasm. This toxic product is then converted to the relatively inert acetate by aldehyde dehydrogenase

(some is metabolised in the stomach - the stomach lining contains ADH)

Question 24

GLUT2 is a facilitated glucose transporter (glucose carrier). When the glucose concentration goes above 30mM, GLUT2 is up-regulated at the _____ _______ ________, enhancing the capacity of glucose transport

Answer 24

GLUT2 is a facilitated glucose transporter (glucose carrier). When the glucose concentration goes above 30mM, GLUT2 is up-regulated at the brush border membrane, enhancing the capacity of glucose transport.

Question 25

--------- is characterized by loss of adipose tissue and skeletal muscle mass.

Answer 25

**Cachexia** is characterized by loss of adipose tissue and skeletal muscle mass.

Question 26

19? | (pathway)

Answer 26

glycolysis

Question 27

the _____ \_\_\_\_\_ ____ carries nutrients from the intestine to the liver

Answer 27

the **hepatic portal vein** carries nutrients from the intestine to the liver

Question 28

name the 5 amino acids that are exclusively **glucogenic**:

Answer 28

1. Threonine 2. Tyrosine 3. Isoleucine 4. Phenylalanine 5. Tryptophan (T, Y, I, F, W)

Question 29

**Alanine, glycerol and lactate** are precursors of **gluconeogenesis**. Where can you find them in the body?

Answer 29

1. alanine - from muscle 2. glycerol - from adipose tissue 3. lactate - from muscle, RBC's, via the **cori cycle**

Question 30

12? | (pathway)

Answer 30

HMG CoA reductase, can be either: - melvanoate pathway (for cholesterol synthesis) - or ketogenesis

Question 31

Oxaloacetate has the choice to be converted to ---- (gluconeogenesis) if the human body ------- to use energy (ATP) or to ----- (glycolysis) if the human body ------ energy (ATP) a) Acetyl CoA & citric acid b) Lactate or ethanol c) Needs d) Doesn’t need

Answer 31

Oxaloacetate has the choice to be converted to **lactate or ethanol** (gluconeogenesis) if the human body **doesnt need** to use energy (ATP) or to **Acetyl CoA & citric acid** (glycolysis) if the human body **needs** energy (ATP)

Question 32

What will happen to your body's glycogen stores during fasting? Why?

Answer 32

**glycogenolysis**, conversion of glycogen to glucose for energy to supply plasma glucose to tissues (brain, RBC, testes, renal mediulla & embryonic tissues)

Question 33

Fasting requires all the glucose to be synthesized from ------------ precursors

Answer 33

Fasting requires all the glucose to be synthesized from **gluconeogenesis** precursors

Question 34

What is the starting material for gluconeogenesis? a) Amino acids b) Fats c) Lipids d) Oxaloacetate

Answer 34

d) Oxaloacetate

Question 35

Why it is recommended to eat while you drink alcohol? ## Footnote a) Because ethanol makes you feel hungry b) Because ethanol produces low concentration of NADH, which inhibits glycogenesis (supress glycogen production and cause hypoglycaemia) c) Because ethanol produces high concentration of NADH, which inhibits gluconeogenesis (supress glucose production and cause hypoglycaemia) d) Because ethanol produces high concentration of NADH, which inhibits glycogenesis (supress glycogen production)

Answer 35

c) Because ethanol produces high concentration of NADH, which inhibits gluconeogenesis (supress glucose production and cause hypoglycaemia)

Question 36

which fuel is preferred by skeletal and heart muscle at times of **rest:**

Answer 36

Fatty acids | (aerobic environment)

Question 37

ATP is released in ------ and it is consumed in ------. a) Glycolysis b) Gluconeogenesis

Answer 37

ATP is released in **Glycolysis** and it is consumed in **Gluconeogenesis**.

Question 38

What is the end product of glycogen in muscles during **exercise?** a) Acetate b) Amino acids c) Glucose d) Lactate e) Ketonic bodies

Answer 38

d) Lactate - exercise changes the cell to an anaerobic environment (from depleted O2 due to an increased cellular respiration rate) = fermentation of pyruvate to produce **lactate**

Question 39

In the human body, which fuel store is the largest? ## Footnote a) Adipose fat b) Liver glycogen c) Muscle glycogen d) Muscle protein

Answer 39

d) Muscle protein

Question 40

Although costly in Phosphate bonds (net 4), the ____ \_\_\_\_ allows the organism to accommodate to large fluctuations in energy needs of skeletal muscle between rest and exercise

Answer 40

Although costly in Phosphate bonds (net 4), the **cori cycle** allows the organism to accommodate to large fluctuations in energy needs of skeletal muscle between rest and exercise

Question 41

What is the fuel of the brain in case of starvation? a) Glucose b) Glycogen c) Glucose 6-phosphate d) Ketone bodies e) Starch

Answer 41

d) Ketone bodies

Question 42

Which organ does all the following? 1. Synthesises glucose 2. Stores glycogen 3. Produces ATP 4. Secrets wastes 5. Provides fuel to brain, muscle and other organs

Answer 42

liver

Question 43

In a starvation state, once TAG stores are depleted, ______ degradation accelerates which will eventually lead to death due to loss of heart, liver, and kidney function

Answer 43

In a starvation state, once TAG stores are depleted, **protein** degradation accelerates which will eventually lead to death due to loss of heart, liver, and kidney function

Question 44

After **40 days of starvation**, the brain gets \_\_\_% of its energy from ketone bodies

Answer 44

After 40 days of starvation, the brain gets **70%** of its energy from ketone bodies

Question 45

\_\_\_\_\_\_\_\_\_ _______ uses ATP to do mechanical work

Answer 45

**skeletal muscle** uses ATP to do mechanical work

Question 46

In glucose synthesis from glucose-6-phosphate, glucose 6-phosphatase is activated by ----------- (metal cation)

Answer 46

Mg²⁺

Question 47

The process whereby precursors such as lactate, pyruvate, glycerol, and amino acids are converted to glucose is termed \_\_\_\_\_\_\_\_\_\_\_

Answer 47

Gluconeogenesis

Question 48

What is the main hormone secreted to increase the blood glucose level? a) Glucagon b) Growth hormone c) Insulin d) Oestrogen

Answer 48

a) Glucagon

Question 49

Where in body you can find mostly triacylglycerol?

Answer 49

adipose tissues

Question 50

the _____ processes fats, CHO's and proteins from the diet, synthesises ans distributes lipids, ketone bodies and glucose for other tissues & converts excess nitrogen (ammonia) to urea.

Answer 50

the **liver** processes fats, CHO's and proteins from the diet, synthesises ans distributes lipids, ketone bodies and glucose for other tissues & converts excess nitrogen (ammonia) to urea.

Question 51

Acetone, acetoacetate and β-hydroxybutyrate are classified as -------

Answer 51

ketone bodies

Question 52

In the **Cahill Cycle**, blood transfers glucose from ----- a) Liver to muscle b) Muscle to liver c) Muscle to pancreas d) Pancreas to liver

Answer 52

a) Liver to muscle

Question 53

21? | (pathway)

Answer 53

Pentose phosphate pathway

Question 54

Gluconeogenesis costs __ ATP to produce **one** glucose molecule

Answer 54

Gluconeogenesis costs **6 ATP** to produce one glucose molecule

Question 55

In humans, two amino acids are exclusively ketogenic:

Answer 55

Lysine & Isoleucine

Question 56

the human body has 'reserves' for starvation for \_\_\_-\_\_\_ months, however our glucose reserves are exhausted after ___ day/s

Answer 56

the human body has 'reserves' for starvation for **1 - 3 months**, however our glucose reserves are exhausted after **1 day**

Question 57

In glucose synthesis from glucose-6-phosphate, glucose 6-phosphatase is activated by: a) Ca++ b) Mg++ c) Na+ d) K+

Answer 57

b) Mg++

Question 58

for the average person (70kg), liver glycogen lasts approximately __ hours

Answer 58

for the average person (70kg), liver glycogen lasts approximately **3 hours**

Question 59

Ethanol consumption leads to an accumulation of NADH, which leads to what **3 metabolic factors:**

Answer 59

1. **inhibits gluconeogenesis** (prevent oxidation of lactate to pyruvate) -\> lactate accumulates 2. **inhibits fatty acid oxidation** -\> stimulates fatty acid synthesis in liver -\> TAG accumulates -\> fatty liver 3. **block the processing of acetyl-CoA** by citric acid cycle, thus ketone bodies were generated in blood and pH drops.

Question 60

during starvation, the human body's **second priority** after providing sufficient glucose to the brain, is to:

Answer 60

preserve protein by shifting from utilization of glucose to utilization of fatty acids + ketone bodies (Figure B)

Question 61

In acid-base homeostasis, ketone bodies can cause --------

Answer 61

Metabolic acidosis | (ketoacidosis)

Question 62

What is the organ that consumes most glucose in the body? a) Brain b) Kidney c) Liver d) Lung e) Pancreas

Answer 62

a) Brain

Question 63

What is the net cost of phosphate in Cori Cycle?

Answer 63

4 pi

Question 64

What are the dangers for other organs (excluding the brain) to use ketone bodies during a prolonged starvation state?

Answer 64

Ketone bodies are acidic = decreases blood pH = enzymes may not be able to function optimally (enzyme inhibition)

Question 65

Glucose 6-phosphate is catalyzed with glucose 6-phosphatase yielding ------- a) Fructose b) Fructose 6-phosphate c) Glucose d) Glycogen e) Lactose

Answer 65

c) Glucose

Question 66

Glycogen is broken-down in the muscles to glucose-6-phosphate (G-6-P). However, G-6-P can’t be converted to glucose in the muscles due to lack of the enzyme --------.

Answer 66

glucose-6-phosphatase

Question 67

what 3 pathways are inhibited during a **fed** state?

Answer 67

Inhibition of: 1. Gluconeogenesis 2. Glycogenolysis 3. Lipolysis

Question 68

during a starvation state (hypoglycaemia), fatty acids can be oxidised to produce _____ \_\_\_\_ via lipolysis (beta oxidation), which is then sent to the _____ mitochondria to be converted into ______ \_\_\_\_\_\_ . Because these are water soluble, they can be easily transported from the liver to other tissues to be re-converted to _____ \_\_\_\_ for energy production (TCA cycle)

Answer 68

during a starvation state (hypoglycaemia), fatty acids can be oxidised to produce **Acetyl CoA** via lipolysis (beta oxidation), which is then sent to the **liver** mitochondria to be converted into **ketone bodies**. Because these are water soluble, they can be easily transported from the liver to other tissues to be re-converted to **Acetyl CoA** for energy production (via TCA cycle)

Question 69

2?

Answer 69

**Fructose 6-phosphate** up arrow = Gluconeogenesis, down arrow = glycolysis

Question 70

1?

Answer 70

Glucose 1-phosphate | (Glycogenolysis)

Question 71

Gluconeogenesis releases energy, whereas glycolysis consumes energy. a) True b) False

Answer 71

a) False gluconeogenesis **consumes energy** (endergonic) glycolysis **releases energy** (exergonic - 96.2 kJ/mol)

Question 72

Irreversible reactions during glycolysis must be bypassed during ---------- a) Hydrolysis b) Gluconeogenesis c) Glycogenesis d) Phosphorylation

Answer 72

b) Gluconeogenesis

Question 73

How does the human body regulate/inhibit glycolysis?

Answer 73

Once the human body has enough ATP (glycolysis pathway is no longer needed), the produced ATP will **allosterically inhibit** the enzymes responsible in glycolysis in step 1 **(Hexokinase)**, step 3 **(Phosphofructokinase/PFK-1)** and step 10 **(Pyruvate kinase)** and thus saves the energy consumed in these steps

Question 74

Which organ has the most important site for **gluconeogenesis during starvation?** ## Footnote a) Brain b) Kidney c) Liver d) Lung e) Muscles

Answer 74

kidney (provides 50% of blood glucose via GNG)

Question 75

Which hormone do you expect to function in case of high concentration of plasma glucose? What do you call this process? a) Glucagon, glycolysis b) Glucagon, gluconeogenesis c) Insulin, glycolysis d) Insulin, gluconeogenesis

Answer 75

c) Insulin, glycolysis

Question 76

Which organ has the most important site for gluconeogenesis during starvation?

Answer 76

kidneys

Question 77

Brain and muscles don’t have glucose-6-phosphatase and accordingly they can’t synthesize glucose. ## Footnote a) True b) False

Answer 77

a) True

Question 78

in the **cori cycle**, Lactate produced from ______ passes via the blood to the liver, where it may be converted to \_\_\_\_\_\_\_

Answer 78

in the cori cycle, Lactate produced from **pyruvate** passes via the blood to the liver, where it may be converted to **glucose**

Question 79

Insulin stimulates all the following Except: ## Footnote a) Gluconeogenesis b) Glycogenesis c) Glycolysis d) Lipogenesis e) Protein synthesis

Answer 79

a) Gluconeogenesis (only catabolic pathway, insulin is anabolic)

Question 80

**8 - 24 hours** without food is called the ____ \_\_\_\_\_\_ state

Answer 80

8 - 24 hours without food is called the **early fasting state**

Question 81

The process whereby precursors such as **lactate, pyruvate, and amino acids** are converted to glucose is termed a) Glycolysis b) Glycogenesis c) Glycogenolysis d) Gluconeogenesis

Answer 81

d) Gluconeogenesis

Question 82

During gluconeogenesis, Glycogen is stored in------- a) Brain and spleen b) Liver and muscle c) Liver and spleen d) Pancreas and spleen

Answer 82

b) Liver and muscle

Question 83

During glycolysis, step 1 & 3 lose __ ATP (1 ATP each), whereas step 10 makes __ ATP, so the overall will be ___ ATP

Answer 83

During glycolysis, step 1 & 3 lose **2** ATP (1 ATP each), whereas step 10 makes **4** ATP, so the overall (net) will be **2** ATP

Question 84

Gluconeogenesis produces energy, whereas glycolysis consumes energy. a) True b) False

Answer 84

b) False GNG **consumes energy** to increase plasma glucose glycolysis **produces energy** from glucose (net 2 ATP & 2 NADH)

Question 85

In citric acid cycle, -------- can be synthesized from alanine, pyruvate, asparagine and aspartate. On the other hand, it can produce acetyl-CoA and glucose.

Answer 85

In citric acid cycle, **oxaloacetate** can be synthesized from alanine, pyruvate, asparagine and aspartate. On the other hand, it can produce acetyl-CoA and glucose.

Question 86

**Name the pathway:** ## Footnote Muscles degrade to amino acids for energy which releases nitrogen. The nitrogen byproduct is transaminated by ALT (alanine aminotransferase) to pyruvate (product of glycolysis) to form alanine. This alanine is shuttled to the liver where the nitrogen bound to alanine is removed to enter the urea cycle and the pyruvate is used to make glucose. This pathway is used instead of the Cori cycle only when an aminotransferase (ALT/AST) is present and when there is a need to transfer ammonia to the liver.

Answer 86

Alanine cycle or Cahill cycle

Question 87

State two types of cells that don’t need the presence of insulin to uptake glucose?

Answer 87

brain & liver -also red blood cells & kidneys

Question 88

Glycogen is broken down in the **muscle** to glucose-6-phosphate (G6P). However, G6P can’t be converted to glucose due to a lack of: a) ATP b) NADH c) Glucose-6-phosphatase d) Glucose-1-phosphatase

Answer 88

Glycogen is broken down in the muscle to glucose-6-phosphate (G6P). However, G6P can’t be converted to glucose due to a lack of **Glucose-6-phosphatase in the muscle**

Question 89

What is the organ that stores the most **glycogen** in the body? a) Brain b) Liver c) Lung d) Muscle e) Pancreas

Answer 89

d) Muscle

Question 90

In the human body, which fuel store can last for longer time? a) Adipose fat b) Liver glycogen c) Muscle glycogen d) Muscle protein

Answer 90

a) Adipose fat

Question 91

---------- is produced from fatty acids, glucose (glycolysis to pyruvate), amino acids, ketone bodies, oxaloacetate, and ethanol. It is an important product for the synthesis of ATP and citrate via Krebs Cycle.

Answer 91

acetyl CoA

Question 92

which 3 pathways occur in a **fasted** state:

Answer 92

1. **Glycogenolysis** (breakdown of glycogen to glucose, 12-24 hrs) 2. **Gluconeogenesis** (synthesis of glucose from A.A., lactate, glycerol, etc) 3. **Lipolysis** (breakdown of lipids)

Question 93

Glucose-6-Phosphate is not converted to glucose in muscles due to lack of

Answer 93

Glucose-6-phosphatase

Question 94

14? | (pathway)

Answer 94

melvanoate pathway/cholesterol synthesis

Question 95

15? | (pathway)

Answer 95

glycogenolysis

Question 96

11? | (pathway)

Answer 96

TCA/krebs cycle (CO₂ is the eventual byproduct in this pathway)

Question 97

The Cori Cycle operates during ---- a) Exercise b) Sleeping c) Thirst

Answer 97

a) Exercise

Question 98

When fasting, muscle and liver tissue use _________ when **blood glucose is low.** a) Fatty acids as a fuel then glycogen b) Glycogen as a fuel then fatty acids c) Glycogen as a fuel then glucose d) Proteins as a fuel then glycogen

Answer 98

b) Glycogen as a fuel then fatty acids | (stimulated by glucagon)

Question 99

Fasting requires all the glucose to be synthesized from -------- precursors? a) Carbohydrate b) Glucose c) glycogen d) Non-Carbohydrate

Answer 99

d) Non-Carbohydrate

Question 100

How does the liver work during vigorous exercise? During vigorous exercise, the liver transforms lactate to glucose via --- a) Cahill cycle b) Citric acid cycle c) Cori cycle d) Krebs cycle e) Pyruvate cycle

Answer 100

c) Cori cycle

Question 101

Where is **glycerol** most likely to be found in the body? a) Adipose tissue b) Muscle c) RBCs d) Erythrocytes e) Heart

Answer 101

a) Adipose tissue

Question 102

The Cori cycle normally accounts for 20% of glucose turnover, but this has been shown to be increased to 50% in ------------ patients.

Answer 102

The Cori cycle normally accounts for 20% of glucose turnover, but this has been shown to be increased to 50% in **cachexia/cachexic cancer patients.**

Question 103

VLDL requires glucose to be stored in adipose tissues as \_\_\_\_\_\_\_\_\_\_\_\_.

Answer 103

VLDL requires glucose to be stored in adipose tissues as **TAG's**

Question 104

The muscles use the Cahill cycle to get rid of -------

Answer 104

Ammonia

Question 105

When the glucose concentration goes above 30mM, ------ is up-regulated to transport glucose to the plasma. a) GLUT1 b) GLUT2 c) GLUT3 d) GLUT4

Answer 105

b) GLUT2

Question 106

Cori cycle occurs during anaerobic time (e.g. exercise), where lactate is produced in RBCs and -----. Lactate is then goes to the ----where it gets converted to -----. a) Adipose tissue b) Muscle c) Liver d) Glucose e) Glycogen

Answer 106

Cori cycle occurs during anaerobic time (e.g. exercise), where lactate is produced in RBCs and **muscle**. Lactate is then goes to the **liver** where it gets converted to **Glucose**.

Question 107

What are the three types of ketone bodies?

Answer 107

acetoacetate betahydroxybutyrate acetone

Question 108

In the Cori Cycle, how many phosphate ions are consumed? (net) a) 1 b) 2 c) 3 d) 4 e) 6

Answer 108

d) 4

Question 109

After fasting/hunger, all processes are catabolic/degradation of molecules except: a) Lipolysis b) Gluconeogenesis c) Glycogenolysis d) Glycolysis

Answer 109

b) Gluconeogenesis

Question 110

Brain and muscles don’t have the enzyme ------------- and accordingly they can’t synthesize glucose.

Answer 110

Brain and muscles don’t have the enzyme **glucose-6-phosphate** and accordingly they can’t synthesize glucose.

Question 111

---------is characterized by loss of adipose tissue and skeletal muscle mass. a) Diabetes b) Arthritis c) Cachexia d) Diabetic e) Glucoma

Answer 111

c) Cachexia

Question 112

the 3 types ketone bodies are:

Answer 112

1. Acetone 2. Beta-hydroxybutyrate 3. Acetoacetate

Question 113

In diabetes mellitus, **type I** is characterized by \_\_\_\_\_\_\_\_\_, whereas **type II** is characterized by \_\_\_\_\_\_\_\_\_\_\_ ## Footnote a) Deficiency of insulin, tissue resistance to insulin b) High level of glucose, low level of glucose c) Low level of glucose, high level of glucose d) Tissue resistance to insulin, deficiency of insulin

Answer 113

In diabetes mellitus, type I is characterized by **deficiency of insulin**, whereas type II is characterized by **tissue resistance to insulin**

Question 114

In the fasted/starvation state, _______________ cleaves TAG's stored in adipose tissue to produce gycerol and fatty acids which are then sent to the liver to be used as fuel. (lipolysis)

Answer 114

In the fasted/starvation state, **hormone-sensitive lipase** cleaves TAG's stored in adipose tissue to produce gycerol and fatty acids which are then sent to the liver to be used as fuel. (lipolysis)

Question 115

In the citric acid cycle, _________ can be synthesized from **alanine, pyruvate, asparagine and aspartate**. On the other hand, it can produce acetyl-CoA and glucose. (Gluconeogenesis)

Answer 115

In the citric acid cycle, **oxaloacetate** can be synthesized from alanine, pyruvate, asparagine and aspartate. On the other hand, it can produce acetyl-CoA and glucose. (Gluconeogenesis)

Question 116

When our body needs glucose, glucagon (hormone) stimulates ________ to hydrolyse the triglycerides to fatty acids and glycerol, then later can then be transformed to glucose in the _____ cells. a) Adipose tissue b) Muscle c) Liver d) Lipase e) Hydrolase

Answer 116

When our body needs glucose, glucagon (hormone) stimulates **lipase** to hydrolyse the triglycerides to fatty acids and glycerol, then later can then be transformed to glucose in the **liver** cells.

Question 117

\_\_\_\_\_\_\_\_\_ ______ synthesises, stores, and mobilses triacylglycerols

Answer 117

**adipose tissue** synthesises, stores, and mobilses triacylglycerols

Question 118

Glucagon **stimulates** all of the following Except: ## Footnote a) Gluconeogenesis b) Glycogenolysis c) Glycolysis d) Lipolysis

Answer 118

c) Glycolysis - glucagon is stimulated by a decreased blood glucose, so it will in turn stimulate pathways that **increase** blood glucose

Question 119

After fasting, and when the body needs glucose, which of the following is most likely to occur? a) Gluconeogenesis b) Glycogenesis c) Lipogenesis d) Protein synthesis

Answer 119

a) Gluconeogenesis

Question 120

In the Cori Cycle, lactate is produced in the ----------- (organ) and it is converted to ---------- (carbohydrate). a) Muscle, glucose b) Muscle, glycogen c) Kidneys, glucose d) Liver, glycogen e) Liver, glucose

Answer 120

In the Cori Cycle, lactate is produced in the **liver** (organ) and it is converted to **glucose** (carbohydrate).

Question 121

Glycerol is converted to Glycerol 3-phosphate by the enzyme ______ \_\_\_\_\_\_ \_\_\_\_\_\_

Answer 121

Glycerol is converted to Glycerol 3-phosphate by the enzyme **Hepatic glycerol kinase**

Question 122

Ethanol can’t be fully excreted by the kidneys and its excess can cause ------- damage.

Answer 122

Ethanol can’t be fully excreted by the kidneys and its excess can cause **liver damage.**

Question 123

Normal blood glucose levels are between \_\_\_\_\_**mmol/L.** * Above ___ mmol/L is called **Hyperglycemia** * Below ___ mmol/L is called **Hypoglycemia**

Answer 123

Normal blood glucose levels are between **4.0-7.8 mmol/L.** * Above **7.8 mmol/L** is called Hyperglycemia * Below **4.0 mmol/L** is called Hypoglycemia

Question 124

synthesizing glucose from non-carbohydrate precursors is termed ------- a) Glycolysis b) Gluconeogenesis c) Glycogenesis d) Glycogenolysis

Answer 124

b) Gluconeogenesis

Question 125

Which hormone do you expect to function in case of low concentration of plasma glucose? What do you call this process? a) Glucagon, glycolysis b) Glucagon, gluconeogenesis c) Insulin, glycolysis d) Insulin, gluconeogenesis

Answer 125

b) Glucagon, gluconeogenesis

Question 126

1? | (pathway)

Answer 126

glycogenolysis, then glycolysis

Question 127

9? | (pathway)

Answer 127

lipogenesis (acetyl coa molecules and glycerol are bonded by enzymes to 'build' triacylglycerols)

Question 128

**2 hours** after a meal is called the ___________ state

Answer 128

2 hours after a meal is called the **postabsorptive state**

Question 129

Alcohol can be dangerous to your health. Ethanol can’t be fully excreted by the ______ and must be metabolized by the \_\_\_\_\_. Its excess can cause ______ damage. ## Footnote a) Brain b) Heart c) Kidney d) Liver e) Pancreas

Answer 129

Alcohol can be dangerous to your health. Ethanol can’t be fully excreted by the **kidneys** and must be metabolized by the **liver**. Its excess can cause **liver** damage.

Question 130

What is the main fuel for the brain in case of starvation?

Answer 130

ketone bodies

Question 131

3?

Answer 131

6-phosphogluconate | (PPP)

Question 132

Which hormone is most likely to be secreted during the fed state? ## Footnote a) Glucagon b) Growth hormone c) Insulin d) Oestrogen

Answer 132

c) Insulin

Question 133

Ethanol consumption leads to accumulation of high concentration of ----------, which inhibits gluconeogenesis.

Answer 133

Ethanol consumption leads to accumulation of high concentration of **NADH,** which inhibits gluconeogenesis.

Question 134

**Glucagon and insulin** were secreted by which of the following cells, respectively? ## Footnote a) α-cells and β-cells b) β-cells and α-cells c) γ-cells and β-cells d) α-cells and γ-cells

Answer 134

a) α-cells and β-cells

Question 135

7? | (pathway)

Answer 135

Cahill/glucose-alanine cycle toxic ammonia is transferred from alanine via alanine aminotransferase (ALT) to produce pyruvate in the liver, the ammonia is then disposed of via the urea cycle.

Question 136

why cant **muscle & brain cells** carry out gluconeogenesis?

Answer 136

Because they doesn’t contain the enzyme **glucose 6-phosphatase**

Question 137

'an important site of gluconeogenesis during starvation as it produces half of the blood glucose' is the?

Answer 137

kidney

Question 138

When the glucose concentration goes above ------ mM, GLUT2 is up-regulated to transport glucose to the plasma.

Answer 138

When the glucose concentration goes above **30mM**, GLUT2 is up-regulated to transport glucose to the plasma.

Question 139

4? | (pathway)

Answer 139

gluconeogenesis

Question 140

Glycolysis produces ----- ATP, whereas gluconeogenesis consumes ------ ATP. a) 2 b) 4 c) 6 d) 8 e) 32

Answer 140

Glycolysis produces **2** ATP, whereas gluconeogenesis consumes **6** ATP.

Question 141

20? | (pathway)

Answer 141

gluconeogenesis

Question 142

The ------------- stores most of the glycogen in the body

Answer 142

The **muscle** stores most of the glycogen in the body

Question 143

You've just finished a large meal (fed state), will **Acetyl CoA** be activated or inhibited?

Answer 143

activated - increased blood glucose = increased insulin = activation of anabolic pathways. - Acetyl CoA will be used for **lipogenesis** (conversion to malonyl CoA for fatty acid synthesis)

Question 144

How many reactions must be bypassed during gluconeogenesis? a) 1 b) 2 c) 3 d) 4 e) 5

Answer 144

3 steps (1, 3, 10) (three kinases)

Question 145

**Glycogenesis** is the formation of -------- ## Footnote a) Glucose b) Glycogen c) Glucose 1-phosphate d) Glucose 6-phosphate

Answer 145

b) Glycogen

Question 146

the _______ secretes insulin (beta cells within the islets) and glucagon (alpha cells within the islets) in response to changes in blood glucose concentration.

Answer 146

the **pancreas** secretes insulin (beta cells within the islets) and glucagon (alpha cells within the islets) in response to changes in blood glucose concentration.

Question 147

After a breakfast (re-fed state), which of the following hormones is most likely to increase? a) Glucagon b) Growth hormone c) Insulin d) Oestrogen

Answer 147

c) Insulin

Question 148

the _____ \_\_\_\_\_\_\_\_ absorbs nutrients from the diet & moves them into the blood or lymphatic system

Answer 148

the **small intestine** absorbs nutrients from the diet & moves them into the blood or lymphatic system

Question 149

the _____ transports ions to maintain membrane potential & integrates inputs from the body and surroundings. it also sends regulatory signals to other organs to determine which organ recieves fuel from where

Answer 149

the **brain** transports ions to maintain membrane potential & integrates inputs from the body and surroundings. it also sends regulatory signals to other organs to determine which organ recieves fuel from where

Question 150

Glucagon and insulin are secreted by which of the following cells, respectively?

Answer 150

glucoagon = alpha cells insulin = beta cells

Question 151

the ________ \_\_\_\_\_\_ carries lipids from the intestine to the liver

Answer 151

the **lymphatic system** carries lipids from the intestine to the liver

Question 152

In diabetes mellitus, type II is characterized by ------------------ insulin.

Answer 152

In diabetes mellitus, type II is characterized by **tissue resistance to insulin**.

Question 153

in a fasted state, does glucagon activate or inhibit acetyl CoA?

Answer 153

inhibit - glucagon is a catabolic hormone which stimulates lipolysis fro fuel during a fasted state, thus preventing Acetyl CoA from being used in lipogenesis

Question 154

Triacylglycerols are stored in the adipose tissue during a ______ state whereas they are released into the blood during a ______ state as free fatty acids (FFA) and glycerol

Answer 154

Triacylglycerols are stored in the adipose tissue during a **fed** state whereas they are released into the blood during a **fasted/starvation** state as free fatty acids (FFA) and glycerol

Question 155

name the hormone: 1. signals fed state 2. stimulates storage of fuels and synthesis of proteins 3. high level = glucose enters muscle + adipose tissue (synthesis of TAG 4. stimulates glycogen synthesis in muscle + liver 5. suppresses gluconeogenesis by the liver 6. accelerates glycolysis in liver -\> increases synthesis of fatty acids 7. accelerates uptake of blood glucose into liver = glucose 6-phosphate more rapidly formed than level of blood glucose rises = built up of glycogen stores (glycogenesis)

Answer 155

Insulin

Question 156

In a refed state, what would be the order of pathways? ## Footnote a) Gluconeogenesis followed glycolysis b) Glycolysis followed by glycogenesis c) Glycogenesis followed by glycolysis d) Glycolysis followed by Glycogenolysis e) Glycolysis followed by gluconeogenesis

Answer 156

b) Glycolysis followed by glycogenesis | (lecture page is wrong)

Question 157

The ------------- uses most of the glucose produced in the body

Answer 157

The **brain** uses most of the glucose produced in the body

Question 158

16? | (pathway)

Answer 158

either glycogenesis, glycolysis or PPP

Question 159

name the 3 stages of liver damage:

Answer 159

1. **development of fatty liver** (inhibit liver functions) 2. **alcoholic/non alcoholic hepatitis** (liver cell death) 3. **cirrhosis** (urea cycle is inhibited = accumulation of toxic ammonia)

Question 160

18? | (pathway)

Answer 160

glycogenesis

Question 161

Which organ does all the following? 1. Converts **inactive Vit D3** (25(OH)-VitD3) to **active VitD3** (1,25(OH)-VitD3) 2. Filters blood plasma 3. Produces urine 4. Secrets wastes 5. Responsible of gluconeogenesis during starvation

Answer 161

kidney

Question 162

\_\_\_\_\_\_\_\_ ______ is the body's major source of TAG's for fuel

Answer 162

**Adipse tissue** is the body's major source of TAG's for fuel

Question 163

name the hormone: 1. signals starved state 2. mobilizes glycogen stores (Glycogenolysis) 3. inhibits glycogen synthesis 4. main target organ is liver 5. inhibits fatty acid synthesis 6. stimulates gluconeogenesis in liver 7. large amount of glucose in liver released to blood stream -\> maintain blood-glucose level

Answer 163

Glucagon - stimulated by low blood glucose - secreted by pancreatic alpha cells

Question 164

After **3 days of starvation**, the brain gets approximately \_\_\_% of its energy from ketone bodies

Answer 164

After 3 days of starvation, the brain gets **30%** of its energy from ketone bodies

Question 165

In the **fed** state, Glucose is converted to ______________ to bind with fatty acyl CoA's to produce TAG's which are then stored in adipose tissue.(lipogenesis)

Answer 165

In the fed state, Glucose is converted to **Glycerol 3-phosphate** to bind with fatty acyl CoA's to produce TAG's which are then stored in adipose tissue (lipogenesis)

Question 166

for the average person (70kg), muscle glycogen lasts approxamitely ___ hours

Answer 166

for the average person (70kg), muscle glycogen lasts approxamitely **5 hours**

Question 167

Glycolysis produces ----- ATP, whereas gluconeogenesis consumes ------ ATP.

Answer 167

Glycolysis produces **2ATP,** whereas gluconeogenesis consumes **6ATP.**

Question 168

When the glucose concentration goes above –---- mM, GLUT2 is up-regulated to transport glucose to the plasma. a) 10 b) 20 c) 30 d) 40 e) 50

Answer 168

c) 30 mM

Question 169

during starvation, the body will maintain blood-glucose levels above: \_\_\_ mg/100 ml

Answer 169

during starvation, the body will maintain blood-glucose levels above: ## Footnote **40 mg/100 ml**

Question 170

Cancerous cells became larger in size and consume more _______ (which leads to loss of adipose tissues and skeletal muscles). The tissues act as they are doing exercise, causing anaerobic conditions for the cells so they produce more _____ (a high concentration in blood can be a weak marker of cancerous cells)

Answer 170

Cancerous cells became larger in size and consume more **glucose** (which leads to loss of adipose tissues and skeletal muscles). The tissues act as they are doing exercise, causing anaerobic conditions for the cells so they produce more **lactate** (a high concentration in blood can be a weak marker of cancerous cells)

Question 171

3? | (pathway)

Answer 171

gluconeogenesis

Question 172

When the human body needs energy, the liver makes glucose through gluconeogenesis. Gluconeogenesis doesn’t fully follow the reverse steps of glycolysis and it bypasses steps 1, 3, 10 because their reverse reactions require a) Glucose b) Fructose c) Glycogen d) The most energy e) Carbohydrates

Answer 172

d) The most energy

Question 173

The liver can’t use ketone bodies as a fuel because it doesn’t have the enzyme ------------- to transform acetyl CoA to energy (TCA cycle).

Answer 173

The liver can’t use ketone bodies as a fuel because it doesn’t have the enzyme **beta-ketoacetyl-CoA transferase** to transform acetyl CoA to energy (TCA cycle).

Question 174

During vigorous exercise, the liver transforms lactate to glucose via _____ cycle.

Answer 174

Cori cycle

Question 175

17? | (pathway)

Answer 175

glycogenolysis

Question 176

What is the primary source of blood glucose in case of early fasting state? a) Fructose b) Glucose c) Glycogen d) Starch

Answer 176

c) Glycogen

Question 177

1. Brain 2. nervous system 3. erythrocytes 4. testes 5. renal medulla 6. embryonic tissues - can only utilize ______ \_\_\_\_\_\_\_ as their major or only energy source

Answer 177

plasma glucose

Question 178

During starvation, when glucose is low in concentration, the ____ breaks down fatty acids to produce ______ \_\_\_\_\_\_ (acetone, acetoacetate and β-hydroxyl-butyrate).

Answer 178

During starvation, when glucose is low in concentration, the **liver** breaks down fatty acids to produce **ketone bodies** (acetone, acetoacetate and β-hydroxyl-butyrate).

Question 179

The **Cori cycle** costs __ Phosphate ions in liver for every __ Phosphate ions made available in muscle. The net cost is __ Phosphate ions

Answer 179

The **Cori cycle** costs 6 Phosphate ions in liver for every 2 Phosphate ions made available in muscle. The net cost is 4Phosphate ions

Question 180

During **Glycogenesis**, Glucose is converted to ------ then to --------- then to glycogen ## Footnote a) Glucose 1-phosphate b) Glucose 2-phosphate c) Glucose 3-phosphate d) Glucose 6-phosphate e) 6-Phospho gluconoate

Answer 180

During Glycogenesis, Glucose is converted to **Glucose 6-phosphate** then to **Glucose 1-phosphate** then to glycogen

Question 181

\_\_\_\_\_ is major electron donor in **reductive biosynthesis**

Answer 181

**NADPH** is major electron donor in reductive biosynthesis

Question 182

6? | (pathway)

Answer 182

Cahill/glucose-alanine cycle (pyruvate is used to carry ammonia to the liver as the relatively inert alanine)

Question 183

Ethanol consumption leads to an accumulation of NADH, which inhibits \_\_\_\_\_\_\_\_\_\_

Answer 183

Gluconeogenesis

Question 184

------ & ----- don’t have the enzyme glucose-6-phosphatase and accordingly they can’t synthesize glucose.

Answer 184

Brain & muscles

Question 185

After eating a big meal (fed state), all processes are **synthesis** except: ## Footnote a) Glycogenesis b) Glycolysis c) Lipogenesis d) Protein synthesis

Answer 185

b) Glycolysis

Question 186

The liver doesn’t have the enzyme _________________ aka ________ to transform acetyl CoA to energy (TCA cycle).

Answer 186

The liver doesn’t have the enzyme **β-ketoacyl-CoA transferase aka thiophorase** to transform acetyl CoA to energy (TCA cycle).

Question 187

Between meals and during longer fasts, or after vigorous exercise, glycogen is depleted. ## Footnote a) True b) False

Answer 187

a) true

Question 188

**Glucagon** generally elevates the concentration of glucose in the blood by promoting gluconeogenesis and \_\_\_\_\_\_\_ ## Footnote a) Glycolysis b) Glycogenesis c) Glycogenolysis d) Lipogenesis

Answer 188

Glucagon generally elevates the concentration of glucose in the blood by promoting **gluconeogenesis and Glycogenolysis**

Question 189

Dephosphorylating of **glucose 6-phosphate** yielding glucose is catalyzed by \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_

Answer 189

Dephosphorylating of glucose 6-phosphate yielding glucose is catalyzed by **glucose 6-phosphatase**

Question 190

the liver assists in making ketone bodies, but it can’t use it due to lack of?

Answer 190

beta-ketoacetyl-CoA transferase

Question 191

What is the glucose level in blood in mg/dL? a) 30-100 b) 60-150 c) 100-150 d) 100-200

Answer 191

b) 60-150

Question 192

Ethanol consumption leads to accumulation of high concentration of NADH, which inhibits ____________ by preventing the **oxidation of lactate to pyruvate**. ## Footnote a) Gluconeogenesis b) Glycolysis c) Glycogenolysis d) Glycogenesis

Answer 192

Ethanol consumption leads to accumulation of high concentration of NADH, which inhibits **Gluconeogenesis** by preventing the oxidation of lactate to pyruvate. -this causes an accumulation of lactate

Question 193

5? | (pathway)

Answer 193

cori cycle (fate of pyruvate under anaerobic conditions in muscle & RBC)

Question 194

In humans, two amino acids are exclusively ketogenic: ----------- a) Alanine and glycine b) Leucine and isoleucine c) Lysine and isoleucine d) Leucine and lysine e) Serine and threonine

Answer 194

b) Leucine and isoleucine | (L, I)

Question 195

------- is the universal currency of energy in our body, whereas ---- is a major electron donor in reductive biosynthesis. a) ADP b) ATP c) NADPH d) NAD+

Answer 195

**ATP** is the universal currency of energy in our body, whereas **NADPH** is a major electron donor in reductive biosynthesis.

Question 196

eating after breakfast, to maintain blood glucose levels (lunchtime) is called the ______ state

Answer 196

eating after breakfast, to maintain blood glucose levels (lunchtime) is called the **refed state**

Question 197

Ketone bodies circulating in the blood are picked up by cells and converted back into _____ \_\_\_\_ which then enters the citric acid cycle and is oxidized in the mitochondria for \_\_\_\_\_\_

Answer 197

Ketone bodies circulating in the blood are picked up by cells and converted back into **Acetyl CoA** which then enters the citric acid cycle and is oxidized in the mitochondria for **energy**

Question 198

during lipolysis, fatty acids that are released into the bloodstream from adipose tissue cells are bound to transporter proteins called ________________ complexes

Answer 198

during lipolysis, fatty acids that are released into the bloodstream from adipose tissue cells are bound to transporter proteins called **Fatty acid-albumin** **complexes**

Question 199

The liver plays an important role in producing ketone bodies, but it can’t use ketone bodies as a source of energy. a) True b) False

Answer 199

a) True

Question 200

Muscle and brain tissue do not contain (glucose 6-phosphatase), and so cannot carry out --------- a) Gluconeogenesis b) Glycolysis c) Glycogenesis d) Glycogenolysis

Answer 200

a) Gluconeogenesis

Question 201

Diabetes mellitus, is characterized by \_\_\_\_\_\_\_\_\_\_, which is termed \_\_\_\_\_\_\_\_\_ ## Footnote a) High plasma glucose level, hypoglycaemia b) High plasma glucose level, hyperglycemia c) Low plasma glucose level, hyperglycemia d) Low plasma glucose level, hypoglycemia

Answer 201

Diabetes mellitus, is characterized by **high blood glucose**, which is termed **hyperglycaemia**

Question 202

In the **Cahill cycle**, blood transfers alanine from ------------ a) Liver to muscle b) Muscle to pancreas c) Muscle to liver d) Pancreas to liver e) Liver to brain

Answer 202

c) Muscle to liver

Question 203

2? | (pathway)

Answer 203

cori cycle | (liver)

Question 204

In diabetes mellitus, type I is characterized by ------------------ insulin

Answer 204

In diabetes mellitus, type I is characterized by **a lack of insulin**

Question 205

The glycogen stored in the ------- is made accessible to other organs.

Answer 205

The glycogen stored in the liver is made accessible to other organs.

Question 206

name the 3 pathways that operate exclusively in the cytosol of the cell

Answer 206

1. glycolysis 2. PPP 3. lipogenesis

Question 207

name the 4 pathways that operate exclusively in the mitochondria

Answer 207

1. TCA cycle 2. Oxidative phosphorylation/ETC 3. lipolysis/Beta oxidation 4. ketogenesis

Question 208

name the 2 pathways that operate across both the cytosol and the mitochondria

Answer 208

1. GNG 2. Urea cycle