Harvesting chemical energy

Question 1

What happens to ATP in mitochondria?

Answer 1

In mitochondria, ATP is hydrolyzed into ADP and an inorganic phosphate molecule

Question 2

In summary, how is energy gained for bodily processes?

Answer 2

Cellular respiration is used to generate ATP which in turn provides energy for cellular processes via the transition between substrate ATP and product ADP

Question 3

What is the ATP cycle?

Answer 3

The ATP cycle is the transfer of energy between complex molecules and simple molecules, using ATP

Question 4

What are catabolic reactions

Answer 4

Catabolic reactions transfer energy from complex molecules to ATP - breakdown of complex molecules to simple molecules

Question 5

What kind of reaction is cellular respiration?

Answer 5

A catabolic reaction

Question 6

What are examples of the complex molecules that anabolic reactions transfer energy of ATP to

Answer 6

Glycogen, proteins, and tryglycerides

Question 7

What are examples of simple molecules that form catabolic reactions transfer energy from complex molcules to ATP

Answer 7

Simple molecules such as glucose, amino acids, glycerol and fatty acids

Question 8

What are anabolic reactions

Answer 8

Anabolic reactions transfer energy from ATP to complex molecules - addition of many simple molecules to form complex molecules

Question 9

What are the three main sources of fuel in the body

Answer 9

The three main sources of fuel are carbohydrates (absorbed as simple sugars), proteins (absorbed as amino acids), and fats (absorbed as simple fats)

Question 10

What are carbohydrates broken down and absorbed as

Answer 10

Simple sugars

Question 11

What are proteins broken down and absorbed as

Answer 11

Amino acids

Question 12

What are fats broken down and absorbed as

Answer 12

Simple fats

Question 13

Main steps of fuel transferred to ATP energy

Answer 13

1. organic molecules in food
2. digestion and absorption (heat loss)
3. nutrient molecules in body cells (energy lost in nitrogenous waste)
4. cellular respiration (heat loss)
5. ATP

Question 14

What are the two ways that glucose can be used in the body

Answer 14

1. Cellular respiration -> cellular work
2. Storage for harder times -> glucose cross linked together, called glycogen, in liver and skeletal muscle

Question 15

When glucose in bloodstream goes into the cell, what hormone is it facilitated by

Answer 15

Insulin

Question 16

When storage of harder times goes back to glucose in bloodstream step, what hormone is ti facilitated by

Answer 16

Glucagon

Question 17

What ar the 4 main steps of the conversion of glucose to ATP

Answer 17

1. Glycolysis
2. Pyruvate oxidation
3. Citric acid cycle
4. Electron transport chain

Question 18

Where does glycolysis occur

Answer 18

In the cytosol

Question 19

Is oxygen required in glycolysis

Answer 19

No

Question 20

What reactants are required in glycolysis?

Answer 20

Glucose, 2 ATP, 2 NAD+

Question 21

What products are formed in glycolysis?

Answer 21

2 pyruvate, 4 ATP, 2 NADH

Question 22

What net ATP is produced in glycolysis?

Answer 22

Net of 2 ATP

Question 23

What is pyruvate oxidation and what does it produce

Answer 23

Links glycolysis to the citric acid and forms Acetyl CoA

Question 24

Where does pyruvate oxidation occur

Answer 24

Mitochondrion

Question 25

How many ATP does pyruvate oxidation produce?

Answer 25

0 ATP

Question 26

What are the products of pyruvate oxidation?

Answer 26

PER GLUCOSE MOLECULE: (Acetyl-CoA, carbon dioxide, NADH) x2

Question 27

What is the function of the Acetyl CoA produced in pyruvate oxidation

Answer 27

Enables the 2-carbon acetyl group to enter the citric acid cycle

Question 28

Reactants and products in pyruvate oxidation

Answer 28

Pyruvate + O2 --> (Acetyl-CoA, carbon dioxide, NADH) x2

Question 29

Where does the citric acid cycle occur

Answer 29

In the mitochondrial matrix

Question 30

What is the citric cycle

Answer 30

Acetyl-CoA enters the cycle, forming citric acid with oxaloacetic acid, and then a series of reactions occurs in which the product of one reaction is the substrate for the next

Question 31

What products does the citric acid result in:

Answer 31

Per glucose molecule: * 2 ATP * 6NADH * 2FADH2 * 4 CO2

Question 32

FADH2 and NADH are ____ in the electron transport chain

Answer 32

Electron donors

Question 33

What are the reactants of citric cycle

Answer 33

Oxaloacetic acid

Question 34

The citric cycle completes the extraction of _______

Answer 34

Energy from glucose

Question 35

How much ATP does the citric cycle produce

Answer 35

2 ATP per glucose

Question 36

What is substrate phosphorylation

Answer 36

ATP generated by direct transfer (from a substrate) of a phosphate group to ADP

Question 37

What is oxidative phosphorylation

Answer 37

ATP is generated from the oxidation of NADH and FADH2, and the subsequent transfer of electrons and pumping of proteins

Question 38

__ and __ make ATP via substrate phosphorylation

Answer 38

Glycolysis and citric acid cycle

Question 39

Where does electron transport chain occur

Answer 39

At proteins within the inner membrane

Question 40

What happens in the electron transport chain

Answer 40

* NADH and FADH2 oxidised to donate electrons * e- transfer from protein-to-protein along chain through redox reactions * at each transfer, each e- gives up small amount of energy enabling H+ pumped into intermembrane space * O2 pulls e-down the chain, and is then the final electron acceptor where it is reduced to water

Question 41

__ and __ from glycolysis and the citric cycle are used in electron transport chain

Answer 41

NADH and FADH2

Question 42

What is chemiosmosis

Answer 42

A concentration gradient in which hydrogen ions in the intermembrane space rush down through ATP synthase. This causes 'turbine' within ATP synthase to turn and enables phosphorylation of ADP to generate ATP

Question 43

How much glucose is produced at the end of chemiosmosis

Answer 43

26 or 28 ATP per glucose

Question 44

Is substrate or oxidation phosphorylation more efficient

Answer 44

Oxidation

Question 45

What does the fall of electrons down the chain enable in oxidative phosphorylation

Answer 45

Enables movement of H+ ions into the intermembrane space and generates a proton gradient which "drives" the ATP synthase turbine

Question 46

How is cellular respiration versatile

Answer 46

* can derive energy from that one glucose * fats, proteins and more complex carbohydrates also generate ATP * monomers enter glycolysis and the citric acid cycle at different points

Question 47

What substance is rate limiting for glycolysis

Answer 47

Phosphofructokinase

Question 48

How is the rate of cellular respiration regulated

Answer 48

It is regulated via a negative feedback loop, in which the end product inhibits earlier reactions

Question 49

When is AMP stimulated

Answer 49

When ATP is being used too rapidly

Question 50

What is insulin produced by

Answer 50

Beta cells of Islets of Langerhans in pancreas

Question 51

What is the function of insulin

Answer 51

Promote glucose uptake into cells (for ATP production or liver storage)

Question 52

What is glucagon produced by

Answer 52

Alpha cells in the Islets of Langerhans in pancreas

Question 53

What is the function of glucagon

Answer 53

Stimulates the breakdown of glycogen to increase blood sugar levels

Question 54

Insulin is secreted when blood sugar level is (__) and glucagon is secreted when the blood sugar level is (__).

Answer 54

Increasing and decreasing

Question 55

How does the body respond when homeostasis is disturbed with increasing blood sugar levels

Answer 55

Respond with: * increased rate of glucose transport into target cells * increased rate of glucose use and ATP generation * increased conversion of glucose to glycogen.

Question 56

Where are the effectors located when there is decreasing blood glucose level

Answer 56

Liver, skeletal muscle and adipose cells

Question 57

Where are the effectors located where there is increasing blood glucose level

Answer 57

All body cells

Question 58

How do the effectors respond when there is a decreasing blood glucose level

Answer 58

* increased breakdown of glycogen to glucose (in the liver and skeletal muscle)

Question 59

Hyperglycemia is when there is ___ blood glucose level, and hypoglycemia is when there is a ___ blood glucose level

Answer 59

Increasing and decreasing

Question 60

What is the fasting blood glucose level?

Answer 60

around 4-6 mmol L-1

Question 61

What happens when you lose the function of insulin

Answer 61

* No glucose in cells * No ATP from glucose * No glycogen stored for harder times

Question 62

What is diabetes mellitus

Answer 62

* The ability to produce or respond to the hormone insulin is impaired. * Results in abnormal metabolism of carbohydrates and elevated levels of glucose in the blood

Question 63

What happens in type 1 diabetes

Answer 63

Body does not produce insulin, as beta cells of pancrease are destroyed. Requires insulin replacement

Question 64

What is type 2 diabetes

Answer 64

Body produces insulin, but receptors are non functional (insulin resistance). Can be linked to other pathologies and obesity

Question 65

What percentage of diabetics are type 1 and type 2

Answer 65

5-10% of diabetics are type 1, and most (>90%) are type2

Question 66

What is diabetes mellitus caused by

Answer 66

Lack of functional insulin

Question 67

What happens in diabetes mellitus that leads to its consequences

Answer 67

* Levels of glucose in blood increase due to lack of functional insulin. * Increase blood glucose alters the volume and osmolarity of blood, with subsequent pathological consequences.

Question 68

What are the two symtoms of diabetes mellitus

Answer 68

Significant increased hunger and weight loss

Question 69

Glycolysis and Citric Acid cycle make ATP via ___

Answer 69

Substrate phosphorylation