Biochemistry Video 17

Front 1

What are the three main types of fuels?

Back 1

carbohydrate, protein, and fat

Front 2

What element is the common crossroad for getting energy from fats, proteins, and carbohydrates?

Back 2

acetyl-CoA

Front 3

What happens to acetyl-CoA?

Back 3

it is used up in the TCA cycle

Front 4

What does Acetyl-CoA being used in the TCA cycle produce?

Back 4

2CO2, 3 NADH, and FADH2

Front 5

What are the four stages of producing energy from carbohydrates, proteins, or fat?

Back 5

Stage 1: Glucose, amino acids, and fatty acids…………………………….Stage 2: Acetyl-CoA………………….Stage 3: TCA Cycle………………….Stage 4: Electron Transport Chain

Front 6

How are electrons given to the electron transport chain?

Back 6

they are given by the 3 NADH and FADH2 from the TCA cycle (Krebs cycle)

Front 7

In addition to the electrons, what is another requirement for the electron transport chain to occur?

Back 7

oxygen has to accept the electrons at the end of the chain

Front 8

What is glycolysis?

Back 8

the conversion of glucose to pyruvate

Front 9

In which tissues does glycolysis take place?

Back 9

ALL: red blood cell, muscle, adipose, brain, and liver

Front 10

What does pyruvate change to?

Back 10

Acetyl CoA

Front 11

In the well fed insulin world, what happens to Acetyl CoA?

Back 11

it goes through Krebs cycle and electron transport chain to produce CO2 and ATP

Front 12

What is involved in the conversion of pyruvate to acetyl CoA?

Back 12

Pyruvate Dehydrogenase, THIS IS A VERY IMPORTANT ENZYME

Front 13

How do red blood cells get their energy?

Back 13

They get all their energy from the conversion of glucose to pyruvate.

Front 14

Why do red blood cells only get their energy from the conversion of glycolysis, the conversion of glucose to pyruvate?

Back 14

The lack PDH because they lack mitochondria. Because PDH, Krebs cycle, and the electron transport chain all occur in the mitochondria, the red blood cell lacks all these stages.

Front 15

What happens in the well fed insulin world when the liver has made all of the ATP it needs?

Back 15

The ATP sends negative feedback to the processes that produced it (electron trans. Chain, Krebs cycle, PDH, glycolysis), and it will MAKE STORAGE FORMS OF ENERGY. With the shut down of these processes, glucose and Acetyl-CoA accumulates and will be stored by the liver as glycogen

Front 16

What is glycogen?

Back 16

it is basically a branched polymer of glucose

Front 17

When the liver has enough ATP and stops the Krebs cycle and electron chain and Acetyl CoA and glucagon build up, what does it do with the build up of acetyl CoA?

Back 17

It forms polymers of Acetyl CoA known as fatty acids

Front 18

Where is the glycogen and the fatty acids, both produced in the liver stored?

Back 18

the glycogen is stored in the liver while the fatty acids are stored in the adipose tissue

Front 19

What will the liver put out after a meal and what is it composed of?

Back 19

After it has made its full amount of ATP the Acetyl CoA is made into fatty acids which bind to apoproteins and are secreted as VLDL

Front 20

What is fat made of?

Back 20

fatty acids and glycerol-P

Front 21

What is glycerol-P made of?

Back 21

glucose

Front 22

Why do diabetics have hyperlipidemia?

Back 22

Without glucose in the adipose cell, it is unable to make glycerol, which along with fatty acids is a necessary component of fat. Thus, because it does not have glycrol, the adipose cell is unable to store fat and thus there is hyperlipidemia

Front 23

Why do diabetics have a fatty liver?

Back 23

They are unable to store fat in adipose tissue and thus have hyperlipidemia and try to store fat in the liver instead.

Front 24

What is the main hormone in the postabsorptive state (between meals)?

Back 24

glucagon

Front 25

Where will Red Blood Cells and Brain cells get their glucose from between meals?

Back 25

glucose from the liver……it is the liver that is responsible for distributing glucose in between meals

Front 26

What does the liver use to get it’s ATP in the glucagon world (between meals)?

Back 26

?????

Front 27

What did it use in the well fed state?

Back 27

Between meals, the liver uses fat to make the Acetyl-CoA and get it’s energy, while in the well fed insulin world it used glucose

Front 28

How will the liver get the fatty acids to use between meals?

Back 28

it is realesed from the adipose tissue and carried on albumin back to the liver

Front 29

How does the liver know when it has enough energy to start making glucose to secrete between meals?

Back 29

When enough ATP is produced is stopps the Krebs cycle and the electron chain, and thus the Acetyl CoA builds up. The build up of Acetyl CoA is the signal that tell the liver cell that it can not start to make glucose.

Front 30

What are the sources of the glucose made between meals.

Back 30

The main sources are the conversion of pyruvate to glucose and the breakdown of the stored glycogen

Front 31

Does the Acetyl CoA building up between meals change to pyruvate and then to glucose?

Back 31

NO, sugar will turn to fat through the PDH, but this does not go the other way. Fat cannot turn to sugar.

Front 32

If Acetyl CoA cannot turn to sugar when it builds up in the liver between meals, what does it do?

Back 32

When the liver is completely satisfied with it’s energy, the accumulation of Acetyl CoA will into Ketone bodies which will be put into circulation at the same time as the glucose is being released by the liver

Front 33

What are the ketone bodies used by?

Back 33

The muscle cells love using ketone bodies. The heart muscle functions almost exclusively on ketone bodies in between meals

Front 34

How does tissue take advantage of ketone bodies?

Back 34

it converts the ketone bodoes back into acetyl CoA

Front 35

What are the sources of energy for muscle between meals?

Back 35

ketone bodies, fatty acids, glycogen, etc. they will use anything they can get their hands one to make energy if they need to

Front 36

What are the major sources of pyrovate (beginning of gluconeogenesis) between meals

Back 36

lactate and alanine

Front 37

Where does the lactate, which is converted to pyruvate between meals come from?

Back 37

it is the lactate from the glycolysis in the red blood cell…the glucose converts to pyruvate which is converted to lactate in the red blood cell

Front 38

What is the source of the alanine used to make pyruvate and thus gluconeogenesis between meals?

Back 38

it is the result of protein breakdown in the muscles

Front 39

What is the Cori cycle?

Back 39

It is the cycle of glucose to pyruvate to lactose and then back to pyruvate and then back to glucose. This cycle goes in between the liver and the red blood cell

Front 40

How does glucose get into cells?

Back 40

Glucose transporters

Front 41

In what tissues are glucose transporters 1 and 3 found in and what do they do?

Back 41

These transporters are found in most tissues, especially brain and red blood cells and are responsible for basal uptake of glucase

Front 42

Where is GLUT2 found and what is the significance of this transporter?

Back 42

GLUT2 is found on the liver and Beta cells of the pancreas and it is a low affinity transporter so that all of the glucose from the gut is not absorbed and used by the liver. It allows a great deal of the absorbed glucose to pass the liver and go into the circulation. These transporters are are the Beta cells of the pancrease to insure that insulin will only be released when the blood glucose level is very high

Front 43

Where is GLU4 found and what does it do?

Back 43

it is found on akeletal muscle and adipose tissue. It is the glucose transmitter that responds to insulin. It only works when insulin is in the blood stream

Front 44

How do the GLU4 transporter increase intake of glucose in response to insulin?

Back 44

When there is no insulin, the transporter are stored on vesicles in the cytoplasm of cells. When insulin is present these vesicles fuse with the membrane, thus adding more transporters to the membrane