Protein and Lipid Flashcards
(20 cards)
What are proteins made of?
Chains of amino acids.
How many essential amino acids must come from the diet?
8 essential (plus histidine for infants).
Name 3 essential amino acids.
Tryptophan, methionine, lysine.
What is the ‘All-or-None Rule’ in protein synthesis?
Protein synthesis stops if one amino acid is missing.
How is excess protein handled in the body?
Broken down by the liver through deamination.
What are first-class proteins?
Animal sources: meats, eggs, dairy (contain all essential amino acids).
What are second-class proteins?
Plant sources: nuts, grains, missing at least one essential amino acid.
What is PKU?
A condition where phenylalanine builds up due to a defective enzyme.
Name 2 symptoms of protein deficiency.
Fatigue, oedema, stunted growth.
What are lipids made of?
Fatty acids + glycerol (triglycerides).
What are the two essential fatty acids?
Linoleic (omega-6) and linolenic (omega-3).
Why are fats important in the diet?
Energy, absorb fat-soluble vitamins, build membranes.
What happens to glycerol in fat metabolism?
It can be made into glucose or enter energy cycles.
What happens to fatty acids in fat metabolism?
Broken into 2-carbon units → enter Citric Acid Cycle for energy.
What are ketone bodies?
Byproducts from fat breakdown, used for energy, excess causes ketosis.
What is the function of chylomicrons?
Transport dietary fat from intestines to the body.
What does LDL do?
Delivers fat to tissues; can cause artery deposits (bad cholesterol).
What does HDL do?
Collects cholesterol from tissues, brings it to liver (good cholesterol).
What happens when LDL levels are high?
Risk of cardiovascular disease increases.
What diet change can reduce LDL?
Eating more polyunsaturated fats from plant sources.
