Block 2: Lecture 7 Cell respiration

Question 1

ATP cycle

Answer 1

ATP cycle: the transfer of energy between complex and simple molecules in the body, with ATP as the mediator

Question 2

Catabolic reactions vs anabolic reactions

Answer 2

Catabolic reactions- transfer energy from complex molecules to ATP( break down the larger molecules)

Anabolic reactions-transfer energy from ATP to complex molecules.(building of larger molecules from smaller)

Question 3

two pathways of glucose within the cell

Answer 3

cellular respiration–> cellular work

storage( glucose cross-linked together, called glycogen)

Question 4

how is glucose stored

Answer 4

in the form of glycogen

Question 5

What helps glucose get into the cell from the blood stream

Answer 5

insulin

Question 6

Homeostasis

Answer 6

in general terms: the tendency towards a relatively stable equilibrium between interdependent elements

in context: the ways body regulates glucose levels to keep them in a safe range.

Question 7

4 main steps of conversion of glucose to ATP

Answer 7

1. Glycolysis(breakdown of sugar)- no oxygen required
2. Puryvate oxidation(links 1 & 3 steps together) OXYGEN REQUIRED
3. Citric acid cycle(Krebs cycle) OXYGEN REQUIRED
4. Electron transport chain

Question 8

where does glycolysis occur in the mitochondria?

Answer 8

cytosol( outside the mitochondria)

Question 9

where do pyruvate oxidation and citric acid cycle occur in the mitochondria?

Answer 9

in the matrix

Question 10

where does oxidative phosphorylation happen in the mitochondria?

Answer 10

across inner membrane
4 important proteins in the membrane( ATP synthase turbine, 1 peripheral, 3 integral)
in reality 100-1000nds of proteins like that

Question 11

mitochondria structure

Answer 11

Outer membrane–> intermembrane space–> inner membrane–> matrix inside

Question 12

What are the products of Glycolysis

Answer 12

FROM 1 GLUCOSE MOLECULE:

(Gross 4 ATP made
2 ATP used)
Net ATP= 4-2=2 ATP

2 ATP produced

2 NADH(electron carrier) produced

2 pyruvate molecules produced

( through lysis of glucose molecule, i.e 6 carbon molecule splits into 2 3-carbon molecules)

Question 13

Products of pyruvate oxidation

Answer 13

Per 1 pyruvate molecule( 2 pyruvate molecules from 1 glucose molecule):

1 NADH per pyruvate ( 2 NADH per glucose)

1 CO2 per pyruvate ( 2 CO2 per glucose)

1 ACETYL CoA per pyruvate( 2 per glucose)

Question 14

the function of pyruvate oxidation

Answer 14

acetyl CoA enables the 2-carbon molecule to enter the citric acid cycle

3-carbon pyruvate cannot enter the citric acid cycle

Question 15

Products of citric acid cycle

Answer 15

For each acetyl CoA:

1 ATP( 2 ATP PER GLUCOSE)
3 NADH( 6 NADH PER GLUCOSE)
1 FADH2( 2 FADH2 PER GLUCOSE)
2 CO2( 4 CO2 PER GLUCOSE)

Question 16

FADH2

Answer 16

an electron donor. Enters the electron transport chain at a different site than NADH.

Question 16

FADH2

Answer 16

an electron donor. Enters the electron transport chain at a different site than NADH.

Question 17

in the series of reactions

Answer 17

product of one reaction is substrate for the next

Question 18

Oxidative phosphorylation

Answer 18

ATP is generated from the oxidation of NADH and FADN2 and the subsequent transfer of electrons and the pumping of protons.

OCCURS WITHOUT THE NEED OF A SUBSTRATE, ADP AND PHOSPHATE IONS ABLE TO BE OXIDATIVELY PHOSPHORYLATED TO FORM ATP(ATP SYNTHASE ENZYME) NO SUBSTRATE REQURED. DRIVEN BY A PROTON MOTORFORCE THROUGH THE H IONS IN THE INTERMEMBRANE SPACE

Question 19

Electron transport chain

Answer 19

NADH and FADH2 are oxidized to donate 1 or 2 electrons

Electrons transfer from protein-to-protein along the chain
in a series of redox reactions

At each transfer, each electron gives up a small amount of energy which enables H+ ions to be pumped into the intermembrane space. H+ occumulate in the intermembrane space.

Oxygen “pulls” the electrons down the chain, and is then the final electron acceptor where it is reduced to water

Question 20

Products of oxidative phosphorylation

Answer 20

In the electron transport chain, NADH and FADH2 from glycolysis and citric acid cycle are used

26 or 28 ATP produced( per glucose molecule)

Question 21

chemiosmosis

Answer 21

The hydrogen ions in the intermembrane space rush down their concentration gradient (chemiosmosis) through ATP synthase.
This causes the “turbine” within ATP synthase to turn
The rotation of the ATP synthase turbine enables the phosphorylation of ADP to generate ATP

Question 22

describe the action of CYANIDE

Answer 22

Cyanide disrupts the ability of cells to use oxygen in oxidative phosphorylation. And the cell cannot produce ATP

Question 22

describe the action of CYANIDE

Answer 22

CYANIDE STOPS THE e- TO BE PASSED TO OXYGEN–> NO CELLULAR RESPIRATION–>CELL DIES

Question 23

Maximum ATP per glucose

Answer 23

30 or 32 ATP

Question 24

Phosphofructokinase

Answer 24

an enzyme that is important in regulating glycolysis(This enzyme catalyzes the first unique step in glycolysis, converting fructose-6-phosphate to fructose-1,6-bisphosphate)

• inhibited by citrate and ATP( ie products of cellular respiration) when enough ATP has been produced
• stimulated by AMP( AMP accumulates when ATP is being used rapidly–> more ATP needed)

Question 25

Glucagon

Answer 25

• Hormone produced by alpha cells of Islets of Langerhans in the pancreas
• Function: Stimulates the breakdown of glycogen to increase blood sugar levels. (when blood glucose is low)

Question 26

Insulin

Answer 26

-Hormone produced by beta cells of Islets of Langerhans in the pancreas
• Function: promote glucose uptake into cells (for ATP production or storage in the liver)

Question 27

Diabetes Mellitus

Answer 27

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.

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

Question 28

diabetes measure fasting

Answer 28

≥7mmol/L fasting

Question 29

Type 1 diabetes

Answer 29

• Body does not produce insulin, as beta cells of the pancreas are destroyed, often this is autoimmune, or genetic, or through environmental factors
• Affects 5 – 10 % of diabetics, and onset usually occurs in children or adolescents.
• Requires insulin replacement

Question 30

Type 2 diabetes

Answer 30

• Body produces insulin, but receptors are nonfunctional (insulin resistance)
• Most (>90%) diabetics are Type II, usual adults over the age of 40
• Can be linked to other pathologies and obesity, but not sure how or why

Question 31

symptoms of diabetes mellitus

Answer 31

lack of functional insulin

• significantly increased hunger
• significant weight loss
because glucose is not entering cells for ATP production.

Question 32

Energy released by the electron transport chain is used to pump H+ ions into which location in eukaryotic cells?

Answer 32

INTERMEMBRANE SPACE

Question 33

When DNA is wrapped around eight histone proteins it is known as

Answer 33

NUCLEOSOME

Question 34

HOW DOES DNA INSIDE THE NUCLEUS EXIST MOST OF THE TIME

Answer 34

DNA is normally found as a loosely contained structure called chromatin within the nucleus, where it is wound up and associated with a variety of histone proteins.

Question 35

A cell with a predominance of rough endoplasmic reticulum is most likely producing large quantities of:

Answer 35

proteins for secretion

Question 36

Negative vs positive feedback

Answer 36

Positive feedback occurs to increase the change or output: the result of a reaction is amplified to make it occur more quickly. Negative feedback occurs to reduce the change or output: the result of a reaction is reduced to bring the system back to a stable state

Question 37

Is insulin and glucagon release a negative or positive feedback mechanism?

Answer 37

negative