Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
19 Cards in this Set
- Front
- Back
|
What are the main functions of protein?
|
- Structural support & movement
- Enzymes, hormones & neurotransmitters - Transportation - Fluid and acid-base balance - Energy production/glucose - Immune function |
|
|
What is collagen?
|
In all connective tissue, bone, cartilage, ligaments, tendons, skin...
|
|
|
What is elastin?
|
In connective tissue, blood vessels, lungs, ligaments, skin, bladder, cartilage...
|
|
|
What is keratin?
|
In hair, nails & skin
|
|
|
What are actin and myosin involved in?
|
Contractile proteins in muscle cells.
|
|
|
Proteins acting as catalysts, in immunity..?
|
- enzymes
- hormones - neurotransmitters - antibodies (immunoglobulins) |
|
|
How are proteins involved in transport?
|
In blood they help nutrients move around the body (e.g. haemoglobin transports oxygen)
In the cell membrane they regulate the entry/exit of substances in/out of the cell. They also assist the transport of large or fat soluble molecules across the membrane. |
|
|
How to proteins help maintain fluid balance?
|
Through protein serum albumin (the most abundant plasma protein). It acts to draw fluids back into the bloodstream (from the interstitial space), to maintain the fluid balance.
|
|
|
How to proteins maintain the acid-base balance?
|
Amino acids are amphoteric and can act as both acids and bases.
Proteins minimise charges in cells and blood by picking up or donating H+ ions. |
|
|
How are proteins involved in energy production?
|
Amino acids can be broken down to glucose. It provides a small amount of energy (4 cal/g) and usually only in small amounts.
Remember: proteins aren't stored in the body so must be taken from blood or body tissue. |
|
|
What is deamination?
|
If excess amino acids are consumed they're converted to glucose or fat. The amino group is removed & converted to ammonia (excreted). The remainder forms keto acid (depends on side chain).
|
|
|
How much protein should we consume?
|
0.8g per kg of body weight.
Protein intake should = nitrogen excretion |
|
|
What are enzymes?
|
They are globular proteins that act as biological catalysts.
|
|
|
What are the main functions of enzymes?
|
Involved in:
- digestion of food - energy production - making proteins & body structures - storing nutrients |
|
|
Factors that affect enzyme activity?
|
- temperature
- pH |
|
|
What is competitive inhibition? Non-competetive inhibition?
|
Competitive: Interferes with active site of enzyme so substrate can't bind.
Non-competetive: Changes shape of enzyme so it substrate can't bind. |
|
|
What is proteolytic activation?
|
It's activating an enzyme by peptide cleavage. E.g. something may be released in an inactive form and is activated through cleaving the peptide, making it active.
E.g. trypsin. |
|
|
What is the apoenzyme?
|
The protein part of the enzyme.
|
|
|
What is the cofactor?
|
An ion or organic molecule (vitamins) attached to the apoenzyme.
|
