Chapter 6: Protein

Question 1

Amino acid primary sequence

Answer 1

determined by the amino acid sequence

Question 2

Polypeptide shapes- secondary structure

Answer 2

-determined by weak electrical attractions with chain
-results in twisting folding of protein
-provides strength and rigidity

Question 3

polypeptide tangles - tertiary structure

Answer 3

-Complex structures
-due to side chain properties (hydrophillic)
-maintaining shape required to function

Question 4

Multiple polypeptide Interactions

Answer 4

• interactions between polypeptide chains

Question 5

Protein denaturation

Answer 5

• Disturbs their stability
  -uncoil and lose their shape
  -less functional ability

Question 6

Causes of Protein Denaturation

Answer 6

• Heat
• Acid, Base
• Agitation
• Alcohol, Heavy Metals
  -other agents

Question 7

Mouth and Salivary Glands

Answer 7

Chewing and crushing moisten protein rich foods and mix them with saliva to be swallowed

Question 8

Stomach

Answer 8

HCl uncoils protein stands and activates stsomach enzymes

Question 9

Small Intestine and Pancreas

Answer 9

Pancreatic and small intestinal enzymes split polypeptides further,
then the enzymes on the surface of the small intestine cells hydrolyze these peptides and the cells absorb them

Question 10

HCl

Answer 10

Denatures protein structure
activates pepsinogen to pepsin

Question 11

Pepsin

Answer 11

Cleaves proteins to smaller polypeptides and some free amino acids
inhibits pepsinogen synthesis

Question 12

Enteropeptidase

Answer 12

Converts pancreatic trypsinogen to trypsin

Question 13

Trypsin

Answer 13

-Ihnhibists trypsinogen synthesis
-cleaves peptide bonds next tothe amino acids lysine and arginine
-converts pancreatic procarboxypeptides to carboxpeptidases
-Converts pancreatic chymotrypsinogen

Question 14

Chrymotrypsin

Answer 14

Cleaves peptide bonds next to the amino acids phonylalnine tryosine, tryptophan, methionine, asparagine and histidines

Question 15

Protein Absorption

Answer 15

Amino acids must transport into intestinal cells
-there are specific carries for amino acids and small peptides

Question 16

Once amino acids are in intestinal cells

Answer 16

Used for energy
synthesis of other compounds
unused proteins are sent to the liver via the bloodstream

Question 17

Roles of Proteins

Answer 17

-Building materials for growth and maintanece
- as enzyme to help facilitate or help a reaction to completion
- As hormones messesnger molecules, released in bloodstream to tissues and elicit appropriate responses

Question 18

Regulators of fluid balance

Answer 18

Proteins attract water
-found in blood and plasma
-do not normally cross cell membranes, when they do this causes problems for the body
-fluid balance like edema

Question 19

Acid-Base Regulators

Answer 19

-acceot and release H+ ions to maintain balance
-disruptions may cause acidosis or alkalosis, resulting in coma or death

Question 20

As Transporters

Answer 20

Found in nlood, cell membranes
-carrt nutrients and other molecules
-act as a pump in cell membrane

Question 21

antibodies

Answer 21

invading antigens are destroyed by antibodies
-each antigen = specific antibodies
-molecular memory is called immunity

Question 22

As a source of energy and glucose

Answer 22

Proteins can be sacrificed when needed
-body tissues broken down into amino acids
-gluconerogenesis

Question 23

Using amino acids

Answer 23

-To make other compounds
-for energy and glucose
-to make fat
- deamination reactions
creates annonia and C structure without amaino group

Question 24

Converting ammonia to urea

Answer 24

Ammonia is toxic
-the liver combines ammonia with CO2 to make urea
-Urea is released inti the blood and passes through the kidneys
-direct relationship to dietary protein intake
-water is required

Question 25

Nitrogen balance

Answer 25

nitrogen intake - nitrogen output

Question 26

Conditionally essential amino acids

Answer 26

Tyrosine becomes an essential amino acid if the body doesn't convert phenylanine or if diet it doesn't supply it

Question 27

Protein quality: digestibility

Answer 27

Animal protein- 90-99% soy and legume protein =less than 90% Plant protein 70-90%

Question 28

Amino acid composition

Answer 28

Must get all 9 essential amino acids we do not make partial proteins

Question 29

High quality proteins

Answer 29

animal derived foods and some plant derived foods

Question 30

Complementary proteins A=

Answer 30

Achieved throughout the dayas opposed to each meal

Question 31

measuring protein quality

Answer 31

0-100 100- egg whites, ground beef, chciken, skim milk, tuna

Question 32

Recommendation intakes of protein RDA

Answer 32

0.8 g/kg of healthy body weight increased for various population groups

Question 33

DRI

Answer 33

10-35% daily intake from protein must also ensure consumption of adequate energy daily

Question 34

reasons we need dietary protein

Answer 34

obtain essential amino acids to supply nitrogen to make other proteins

Question 35

Protei Energy undernutrition

Answer 35

insufficient intake of protein, energy or both most commone malnutrition impact on children is poor growth may impact certain adult population

Question 36

Health effects of protein

Answer 36

Heart disease cancer osteoporosis weight control kidney disease

Question 37

protein powders

Answer 37

Commonly whey protein often used post-workout not necessary but can be convenient

Question 38

Amino Acid supplements

Answer 38

Single amino acids do not naturally exist in food s -possibly harmful to the body

Question 39

Difference between proteins and carbs/fats

Answer 39

Nitrogen group that is excreted as urea they are much larger and can fold and configure themselves in unique ways denatured proteins cannot preform functions but can't happen to carbs/fats

Question 40

Protein synthesis

Answer 40

DNA is the templater that determines the amino acid sequence of proteins

Question 41

Translation

Answer 41

the process of mRNA directing the sequence of amino acids and synthesis of protein; the amino acids are collected by tRNA and brought to the ribosomes

Question 42

Transcription

Answer 42

the process of making mRNA from the DNA template

Question 43

Ribosomes

Answer 43

The part of the cell where translation happens and then the completed protein is released

Question 44

DNA

Answer 44

packed with 46 chromosomes segments of DNA are genes genes can be translated into a protein

Question 45

Gene expression

Answer 45

DNA- mRNA- tRNA -Protein genes must be switched on and off

Question 46

single gene disorders

Answer 46

Mutations inherited at birth damage to the individual exerted early in life

Question 47

Multigene disorders

Answer 47

Influence several genes sensitive to interactions with the environment single nucleotide polymorphosis

Question 48

Clinical consideration

Answer 48

-genetic predisposition to specific diseases -personalied therapies based on genetic profile -creation of new medicine for genetic variations -deeper understanding of nutrition and disease pathways -currently look mostly at SNPs