Proteins Flashcards
Proteins accounts for how much body weight?
17%
What do amino acids contain
-Carboxylic acid
-Amino group
-Unique R group which differentiates amino acids
What are the 9 essential amino acids think PVT TIM HiLL
Phenylalanine
Valine
Threonine
Tryptophan
Isoleucine
Methionine
Histidine
Leucine
Lysine
Name 5 protein functions
Structure of body tissues (collagen)
Movement (actin and myosin)
Carrier molecules (haemoglobin)
Storage molecules (ferritin for Iron)
Fluids balance in blood (albumin)
Enzymes
Hormones (insulin) and cell membranes
Immune functions (antibodies)
Clotting mechanisms (clotting factors)
Alternative energy source
Name the 5 glycoproteins
Mucins (protective lubrecating barrier)
ABO blood type antigens
Hormones (LH,FSH,TSH)
Major histocompatibility complex (cell surface receptors involves in adaptive immunity)
Proteoglycans (subclass of glycoprotein ) are bound to glycosaminoglycans found in extra cellular matrix.
Shock absorbers
what is protein deamination?
Deamination = removal of the nitrogen-containing amino group
from amino acids and occurs primarily in the liver.
*When the nitrogen group is removed from the amino acid, ammonia is formed which is very toxic. To then
convert the ammonia to a water-soluble compound, it must go through a series of transformation reactions in the liver known a the ‘urea cycle’ to ensure that it can be excreted by the kidneys.
The less toxic, water-soluble compound formed is ‘urea’,
which is filtered out by the kidneys as part of urine.
remaining fragments of amino acids after deamination can be used to produce what ?
glucose and ketones
what is the urea cycle?
Ammonia formed by deamination needs to be converted to
‘urea’ to ensure its safe removal from the body. This involves
the Urea Cycle, which takes place in hepatocytes (liver cells).
explain transamination
This is an important step
in the synthesis of some
non-essential amino acids. If a particular non-essential amino
acid is not available, the body can make it from another.
* The amino group of an amino acid is transferred onto an
enzyme. The enzyme then transfers the amino group
on to a ketoacid, thus forming the new amino acid.
what vitamin is transamination dependent on?
B6
how would you optimise protein digestion?
-Chew thoroughly and avoid drinking with meals.
- Support stomach acid levels with Zinc and B6-rich foods.
– Apple cider vinegar in a little water before meals.
– Bitter herbs and foods before meals
(These also promote the release of pancreatic juice.)
– Use betaine hydrochloride supplements
what happens to undigested protein
The microbiome contributes to protein metabolism: undigested
protein that reaches the colon is fermented, creating toxic
metabolites that increase the inflammatory response and
encourages the proliferation of opportunistic pathogens
what are the 4 limiting amino acids?
lysine, threonine, methionine, and
tryptophan
what % of protein in the diet is considered excess
20%
why would excess protein cause cancer?
Polycyclic
aromatic hydrocarbons (PAHs) and heterocyclic amines (HCAs)
produced during the high temperature cooking of meat
(e.g. frying, BBQ, high temp-roasting)are carcinogenic.
2 reasons why excess protein would cause skeletal diseases
1)due to the acidic burden of excess animal protein, it can also
draw calcium out of bones and increase the risk of osteoporosis.
2) because of the collagen structure within bone, a protein deficiency can also negatively impact bone health.
why would excess protein cause cardiovascular issues
because of the oxidation and inflammation of the endothelium
why would excess protein cause kidney disease
The extra acidity from a high animal protein
intake needs buffering by the kidneys. The kidneys
must also filter the increased urea that is generated.
apart from protein building what other jobs do amino acids have name 4?
- Contribute to the synthesis of hormones and neurotransmitters.
- Act as neurotransmitters themselves e.g. glycine.
- Act as methyl donors e.g. methionine.
- Build bile acids for digestion (glycine and taurine).
- Act as precursors for nitric oxide production e.g. Arginine.
- Help detoxify thousands of chemicals (i.e. phase 2 liver pathways).
- Act as precursors for the manufacture of endogenous antioxidants.
what amino acid is t is the preferred fuel for rapidly dividing cells such as enterocytes, lymphocytes and macrophages
Glutamine