Exam 3

Question 1

What is the big picture of Protein (AA) metabolism?

Answer 1

AA C skeletons can supply C intermediates to Glycolisis through pyruvate and the TCA cylce

Keep glycolisis and TCA cycle running

Reverse glycolitic and tca cycle intermediates for non-essential amino acids

Question 2

When would body trigger breakdown of protein or amino acids?

Answer 2

Need for energy or glucose, or amino acids are in excess.

Question 3

What does catabolism or deamination of Amino Acids create?

Answer 3

Ammonia

Question 4

Where do you detoxify Ammonia in body? What cycle does it use?

Answer 4

In liver, Urea Cycle

Question 5

How do you get Ammonia safely to the liver?

Answer 5

help of glutamine or alanine

Question 6

Where does bulk of glutamine or alanine come from?

Answer 6

skeletal muscle

Question 7

What form are amino acids usually absorbed in?

Answer 7

Peptides

Question 8

Where are peptides broken down into amino acids?

Answer 8

intestinal cells

Question 9

Who gets the nutrients first?

Answer 9

intestinal cells

Question 10

What is the major Amino Acid that is used for energy in intestinal cells and most abundant?

Answer 10

Glutamine

Question 11

What does the liver use as 50 percent of it’s energy? why?

Answer 11

Amino Acids, because of urea cylce.

Question 12

How does Peptide Transport work? what type of transport is used?

Answer 12

Peptides and Hydrogens move into the cell using transporter.

H + build up is taken out of the cell bringing in Na ions

Na build up uses Na K ATP transporter to take NA out of cell and bring in K

by active transport.

Question 13

What are the essential AA?
(PVT TIM HLL)

Answer 13

Phenylalanine
Valine
Threonine

Tryptophan
Isoleucine
Methionine

Histidine
Leucine
Lysine

Question 14

What does Semi-essential AA mean?

Answer 14

In certain physiological circumstances you can’t make enough of them, but under normal you can

Question 15

Where is Arginine primarily synthesized?

Answer 15

In the kidneys

Question 16

What are the Semi-essential AA?

Answer 16

Arginine, Cysteine, and Tyrosine

Question 17

Where do you make Tyrosine from?

Answer 17

Phenylalanine

Question 18

What is Phenylketonuria (PKU)?

When is it tested and why?

Answer 18

A defect in Phenylalanine Hydroxylase cannot convert Phenylalanine into Tyrosine

Tested at birth may cause irreversible damage

Question 19

What are the dietary recommendations for PKU?

Answer 19

lower Phenylalanine intake, and consume of Tyrosine intake

Question 20

What can high levels of Phenylalanine cause?

Answer 20

intellectual disability, seizures, behavioral problems, mental disorders.

Question 21

What is unique characteristic about Alanine?

Answer 21

it has a Pyruvate skeleton as a carbon skeleton

Very easy to make into Pyruvate for glucose synthesis since it doesn’t have to go through TCA cycle

Question 22

What is unique characteristic about aromatic AA Tyrosine or (Phe) and Ser Thr?

Answer 22

Hydroxyl group (OH), where Phosphate is added by Kinases

Question 23

What is unique characteristic about Val, Leu, and ile

Answer 23

contain branched amino acids (BCAA)

Question 24

What is a unique characteristic about glutamine?

Answer 24

it can carry 2 Nitrogens
can be used to transfer ammonia in a non toxic form to liver for urea cycle
most abundant amino acid and can be synthesized
Important because it can be Non- essential AA and can easily be made and are major energy sources for intestinal and immune cells

Question 25

What is a unique characteristic about Cystine and Methionine?

Answer 25

Cystine has (SH) group that can build disulfide bonds and secondary protein structures Methionine (SH) and methyl group Important for Start AA for protein synthesis and can be used for Methylation reactions

Question 26

What is a unique characteristic about Argenine?

Answer 26

Important for making Urea and Nitric Oxide

Question 27

What are the three ways that Amino Acids can be deaminated? What is required for Deamination?

Answer 27

Lyases, dehydratases, and dehydrogenases. Vitamin B6 as form of PLP

Question 28

What Problems can arise from vitamin B6 deficiancy?

Answer 28

may not be able to deamination and transaminate AA

Question 29

What is the result of Deamination?

Answer 29

Carbon Skeleton and Ammonia

Question 30

What is the result of Transamination

Answer 30

New AA, No ammonia and carbon Skeleton of old AA (Transfers Ammonia)

Question 31

What are the key points of Urea Cycle?

Answer 31

Needs Energy 4 ATP to make 1 Urea Need carbon dioxide Has TCA coupled to ensure suffient energy and intermediates to run Urea cylce supplies CO2 and in return Urea supplies Fumarate

Question 32

What is the benefit of using Pyruvate for glucogenesis rather than any other AA?

Answer 32

Pyruvate can be used to make Oxaloacetate rather than an AA going through a whole cycle to make Oxaloacetate

Question 33

What AA can only be used for Ketogenesis cycle?

Answer 33

Leu and Lys

Question 34

What is a "switch" for AA to be used for Ketogenesis

Answer 34

high levels of Acetyl Coas

Question 35

How do you make NEAA?

Answer 35

you make them by transamination

Question 36

How do you use AA C- skeleton for energy production, gluconeogenesis/ ketone bodies, or fatty acids?

Answer 36

by deamination

Question 37

How do you store AA as fat?

Answer 37

Pyruvate will be turned into Acetyl Coa which will be made into citrate inside cell (once sufficient NADH is made), build up will move outside of cell to form Acetyl coa to make fatty acids

Question 38

What are the 3 ketone bodies that can be produced?

Answer 38

acetone, acetoacetic acid, beta- hydroxybuterate

Question 39

what ketone body is mostly produced when you go into ketogenesis?

Answer 39

beta- hydroxybuterate Will be 10 x more than acetyl coa

Question 40

In regular circumstances, (Not ketogenesis/ NADH are low) what ketone body is produced? how is it expelled out of the body?

Answer 40

Acetoacetate, exhaled by breath

Question 41

Why is fast protein digestion (AA) not beneficial?

Answer 41

you can only take up a certain amount of amino acid per hour and if exceed it will deaminated and stored as fat

Answer 42

glucose can help supply acetyl acetate to maximize efficiency of TCA cycle, without glucose present other

Question 43

*What does the Urea Cycle serve as?

Answer 43

A detoxification cycle for amino acid catabolism

Question 44

*Does urea run at one speed or rate all the time?

Answer 44

No, it fluctuates activity on the increasing or decreasing elimination of ammonia

Question 45

*why is glucagon released?

Answer 45

In response to low glucose levels

Question 46

*when you are not consuming enough glucose where do you synthesize it from? and how do you get them?

Answer 46

Amino acids c-skeletons, by deamination amino acids to go into gluconeogenesis

Question 47

*When you make glucose out of AA c-skeletons (deamination) how do you deal with extra ammonia? Where is it excreted? Does it add stress?

Answer 47

Make it into Urea in Urea Cycle, Kidneys Adds stress onto kidneys because it will have to make more UREA

Question 48

*How does Glucagon promote Urea Cycle?

Answer 48

It promotes it by increasing mRNA for urea cycle enzymes

Question 49

*What is required by BCAA transferase to move amino group to new C-Skeleton? (BCAT)

Answer 49

Vitamin. B6

Question 50

*where is there high activity of BCAT ? where is there low activity? why?

Answer 50

High activity in skeletal muscle, low in liver, brain, and adipose. (Skeletal metabolizes first) Reason BCAA plasma levels rise rapidly (they bypass liver so there is buildup)

Question 51

*What does BCAAs do in skeletal muscle?

Answer 51

BCAT takes isoleucine, transfer to glu to make gln and release ammonia for detox C-skeletons are used to make succinyl

Question 52

*What does BCAAs move from liver to muscle?

Question 53

*What do you give to a person with urea cycle disorder/

Answer 53

phenylbutyrate

Question 54

*What two things does phenylbutyrate do?

Answer 54

get rid but eventually depleat levels of GLN 2. speeds up catabolism of BCAA Makes BCCA to transaminate to keep glu levels up

Question 55

*During trauma etc.

Answer 55

Transfers glutamine to ammonias to liver so BCKA can use to form BCAAs

Question 56

Why is there many different types of AA transporters in the kidneys? How do AA transport?

Answer 56

there are many AA transporters in kidneys to main AA status for growth and repair Only transfer in groups Na dependent or Na independent

Question 57

*What do the kidneys use gln to generate?

Answer 57

Kidneys use gln to generate ammonium used to lower ph because it donate hydrogen ion