5) Biological molecules Flashcards
(26 cards)
Nutrition
ability to make or obtain organic compounds for energy needed for growth and development
Importance of carbohydrates
source of energy for:
1. Muscle contraction
2. Cell division
3. Active transport
4. Protein synthesis
5. Nerve impulse
transmission
Importance of proteins
For growth and tissue repair
Formation of protein molecules
A) enzymes
B) haemoglobin
C) antibodies
D) part of cell membrane such as
carrier proteins ,channel proteins,
receptors
E) some hormones such as insulin ,
and glucagon
Importance of fats
Source of stored energy
A) thermal insulation
B) electrical insulation
C) part of the cell membrane
D) protect vital organs
E) some hormones such
testosterone and oestrogen
What happens to excess amino acids
they are deaminated by break down of excess amino acids in liver, where nitrogen containing part is turned in to ammonia then to urea, to be excreted by kidney and carbohydrate part is stored
Consequences of excess fat intake (Coronary heart disease)
- Excess fat build up on walls of the artery
- Narrowing of arteries and reduce elasticity of walls
- blood pressure increase
- Blood supply to heart muscle is reduced , so less oxygen and glucose reaching to heart muscle , so
less respiration and so less energy for heart muscle to keep contracting - Increasing risk of clotting
- Stop the blood flow to heart muscle ..heart attack
Vitamin C
Importance: Help in formation of
substance called collagen strengthen blood vessels
Keeps gums and teeth healthy
Deficiency:
scurvy, bleeding gums and loss of teeth, and poor healing of wounds
Vitamin D
Importance: Help in absorption of calcium into bones to strengthen bones and teeth
Deficiency: rickets in children , fragile bone in
adults , muscle cramps , weaken immune system .
Iron
Importance: needed to form haemoglobin
Deficiency: Anaemia, Pale yellow face, Shortness of breath, easily fatigue, affected nails
Calcium
Importance: Build strong bones and
teeth promotes blood clotting
Deficiency : Rickets in children and fragile bones in adults and poor blood clotting
Roughages
Importance: stimulates peristalsis
in intestine to move food
Deficiency: Constipation, increasing risk of
colon cancer
Water importance
- to activate enzymes and for metabolic reactions
- Keep our body temperature constant
- Plays a role in digestion
Peristalsis
- Waves of contractions and relaxations of muscle walls of the alimentary canal
- For squeezing and pushing the food forward circular and longitudinal muscles work antagonistically to each other , circular
contract and longitudinal relax food push forward
Balanced diet
Taking in all nutrients in correct amount to provide the energy needed for growth and development to maintain health
Energy is needed according to
1.Age
2.Sex
3.Weather
4.Physical activity
5.Psyclogical change (menstruation & pregnancy)
Obesity causes
1.Coronary heart diseases
2.Heart attack
3.Diabetes
4.High blood pressure
5.Psychological disturbances
Structure of DNA
- Its made from 2 strands made from nucleotides
- With 4 types of bases A, T, G , C
- pair up according to the complementary base pairing rule where A pairs with T. And G pairs with C
- the two strands are held together by hydrogen bonds where they twist to form a double helix
Gene
A specific length of DNA coding for a specific protein
Protein synthesis
mRNA is a copy of DNA
mRNA carry copy of genes
DNA remain in nucleus while mRNA move out of nucleus to cytoplasm then to ribosomes
Ribosome assemble amino acids into specific sequence forming specific protein
DNA analysis
1.Different people have different DNA
2. DNA has genes with specific sequence of bases
3. Organisms that are closely related have more similar base sequence in their DNA
How protein molecules have a specific shape
- Coded by a specific gene that has a specific base sequence
- where mRNA is a copy is this gene which codes for a specific sequence of amino acids
- where the amino acids determines the shape of proteins
- Amino acids joins to form a specific protein that folds
Starch test
Add iodine reagent
Colour change from yellow orange to blue black
Protein test
Add biuret reagent
colour change from blue to purple
Reducing sugars test
Add benedict reagent
heat to 80 degrees
colour change from blue to brick red
