Macro #7 & #8: Proteins and Health Implications

Question 1

Why we need proteins

Answer 1

1. Energy
2. We need essential amino acids for protein synthesis
3. We need certain functional proteins in the body

Question 2

Recommendations

Answer 2

1. 10-35% of our intake
2. Important for growth periods
3. 70-100g per day

Question 3

Amino acids

Answer 3

Monomers of proteins (we have 20)

Question 4

Anatomy of an amino acid

Answer 4

Has
1. An amino group
2. An acid group

Question 5

Essential amino acids

Answer 5

Cannot be made in the body so we must eat them

Question 6

Nonessential amino acids

Answer 6

Can be created in the body. Don’t need to eat it

Question 7

Conditionally essential amino acids

Answer 7

Under certain conditions, the body sometimes can’t make the amino acid so we have to eat it in our diet

Question 8

Protein Quality

Answer 8

Determined by whether a given dietary protein provides all the necessary essential amino acids in adequate amounts

Question 9

Complete proteins

Answer 9

Foods that contain adequate amounts of all nine essential amino acids (most animal proteins and some plant proteins are complete)

Question 10

Incomplete Proteins

Answer 10

Foods that lack one or more of the 9 essential amino acids (grains, wheat, corn, rice, legumes)

Question 11

Primary protein structure

Answer 11

Chain of amino acids

Question 12

Secondary protein strucuture

Answer 12

Folding of the chain into either the alpha helix or beta pleated sheet

Question 13

Tertiary protein structure

Answer 13

Folding of alpha helix and beta pleated sheet

Question 14

Quaternary protein

Answer 14

Protein consisting of more than one amino acid chain

Question 15

Peptide bonds

Answer 15

Bonds that keep amino acids together so they can form proteins

Question 16

Dipeptide chain

Answer 16

Bonding two amino acids

Question 17

Tripeptide chain

Answer 17

Bonding three amino acids

Question 18

Polypeptide chain

Answer 18

Several amino acids bonded in a chain

Question 19

How many proteins can we have coded in our body

Answer 19

~20,000

Question 20

Functional Protein

Answer 20

Protein that has a specific function in the body

Question 21

Protein Digestion Part 1

Answer 21

1. Protein enters the stomach
2. HCL activates pepsinogen and turns it into pepsin
3. HCL denatures (unfolds) the protein
4. Pepsin breaks down protein into smaller polypeptides

Question 22

Protein Digestion Part 2

Answer 22

1. Polypeptides enter small intestine
2. Small intestine releases the hormone cholecystokinin (CCK)
3. CCK causes the release of enteropeptidase from the pancreas

Question 23

What are the pancreatic protease

Answer 23

Trypsinogen
Chymotrypsinogen

Question 24

Protein Digestion part 3

Answer 24

1. Enteropeptidase is released from the enterocytes which contverts trypsinogen and cymotrypsinogen into their active forms: trypsin and chymotrypsin
2. Trypsin and cymotripsin break down polypeptides into dipeptides and tripeptides
3. Dipeptides and tripeptides are absorbed into the enterocytes

Question 25

Enteropeptidase

Answer 25

Converts trypsinogen and chymotrypsinogen into their active forms: trypsin and chymotrypsin

Question 26

Where do amino acids go after traveling through the portal vein?

Answer 26

Amino acid pool

Question 27

How long do amino acids stay in the amino acid pool

Answer 27

They do not stay long. They enter the pool and then immediately exit to other parts of the body

Question 28

What percentage of amino acids go from the pool to the liver

Answer 28

70%

Question 29

What does the liver do with AA

Answer 29

1. Synthesis of proteins
2. Synthesis of non essential amino acids
3. Can oxidize amino acids for energy (turning amino acids into glucose)
4. Can convert glucose into fatty acids because it cant be stores in the skeletal muscle once its full so it converts excess to fatty acids and triglycerides

Question 30

Protein Synthesis

Answer 30

DNA&raquo_space; RNA .. Protein
Transcription and Translation

Question 31

Transcription

Answer 31

DNA is copied by RNA

Question 32

Translation

Answer 32

RNA produces amino acid chain by telling the bases what amino acids to produce

Question 33

Two ways to make new amino acids from old amino acids

Answer 33

Animation
Transanimation

Question 34

Animation

Answer 34

Adding an ammonium group to an amino group which creates a new amino acid

Question 35

Transanimation

Answer 35

Transferring an amino group to a different carbon skeleton thats found in the the amino acid pool to create a new amino acid

Question 36

Where does animation occur?

Answer 36

The liver

Question 37

Where does transanimation occur?

Answer 37

Cells and blood

Question 38

Using protein for energy

Answer 38

Gluconeogenesis. Taking protein and breaking it down into amino acids. Amino acids turn into pyruvate which turns into acetyl coa that can enter the krebs cycle

Question 39

Amino acids turning into pyruvate

Answer 39

Happens in the liver. Removal of the amino nitrogen group from an AA and combing with a different carbon skeleton

Question 40

What happens of you have too much acetyl coa?

Answer 40

It will turn into triglycerides

Question 41

Converting glucose into fatty acids

Answer 41

Removing amino/nitrogen group from the amino acid and then converting the excess nitrogen into urine

Question 42

Urea Cycle

Answer 42

When we remove the nitrogen group to make our new amino acids, we are left with NH4 which is toxic to our body. The liver takes that and converts it into urine to release the nitrogen from the body. Nitrogen increases when protein intake increases

Question 43

Protein Takeover

Answer 43

Balance between muscle protein synthesis and muscle protein breakdown. Breaking down the proteins we don’t need and building the ones we do

Question 44

Cancer cachexia

Answer 44

Involuntary skeletal muscle loss or “wasting”

Question 45

Facts about cancer cachexia

Answer 45

Common in people who have advanced or aggressive cancers
Decreased survival
Decreased efficacy of cancer therapies
Causes weight loss
Loss of skeletal muscle –> loss of balance

Question 46

Cancer cachexia treatment strategies

Answer 46

Consume higher levels of protein than the normal national average (1.0-1.5 g)
Meet with a dietician

Question 47

Age-related sarcopenia

Answer 47

Progressive and generalized loss of skeletal muscle mass and strength

Question 48

Factors affecting normal sarcopenic decline

Answer 48

Anabolic resistance
Decreased protein synthesis
Impaired vascular response
Decreased anabolic hormones

Question 49

Factors accelerating a punctured decline

Answer 49

Insufficient energy
Protein malnutrition

Question 50

Interventions for age-related sarcopenia

Answer 50

Physical exercise
Administration of dietary supplements
Target diet
Protein quality
Adequate leucine intake

Question 51

Timing of protein intake

Answer 51

Protein pacing: consuming protein-containing meals very 3 hours will maximally suppress muscle protein breakdown

Question 52

How much protein is optimal

Answer 52

1.6-2.2 g/kg/day. Any more than that will create excess calories and acetyl coa will create triglycerides

Question 53

Leucine

Answer 53

The building block for skeletal muscle proteins and is a signal for protein synthesis to start/ be “switched on”

Question 54

What happens if you consume large quantities of leucine?

Answer 54

Large amounts of ANY amino acid can saturate our transporters and prevent us from absorbing the other amino acids that we need

Question 55

Amino acids and carrier proteins

Answer 55

Amino acids compete for carrier proteins. The same type of protein can carry multiple amino acids