essay titles

Question 1

The importance of ions in biology

Answer 1

1) sodium ions in co-trasport of glucose
- importance: sodium ion concentration gradient is what drives the movement of glucose into cell

2) sodium ions in osmoregulation, loop of henle maintains sodium ion gradient
- importance: ensures water leaves golmerlaar filtrate, concentrating urine, therfore less water lost

3) calcium ions in synpatic transmission
-importance: stimulates vesicles containing neurotransmitter to move and fuse with presynaptic membrane
- sodium ions in depolarisation of the post synpatic membrane so action potentials can be generated

4) hydrogen ions in respiration and photosynthesis
- oxudative phosphorylation
- importance: vital to ensure chemiosmosis which drives ATP synthesis

Question 2

Th importance of the applications of the study of genes and DNA

Answer 2

1) DNA probes
- what they are, how they are produced
importance: allows genetic screening which can identify genetic disorders and also better treatment reducing overprescribing costs

2) recombinant DNA technology in treating conditions
- what is it
- somatic gene therpy in treating
- production of human insulin in vitro cloning

3) epigenetics
- what is it
importance: developing drugs

4) genetic fingerprinting
- VNTR’s, gel electrophoresis - uses in forensic science, animal and plant breeding, determining genetic variability

Question 3

what is the importance of water and the regulation of water content to organisms?

Answer 3

1) osmoregulation
- water reabsorption at DCT, collecting duct
- loop of henle in maintaining sodium ion concentration
- ADH and its affect on water reabsorption
importance: ensuring not too much fluid lost

2) water potential gradients and osmosis
- what is osmosis
- importance: water moves our of tracheoles in insects by osmosis down water potential gradients, allowing for faster diffusion of gas exchange - describe this process of gas exchange in insect

3) mass transport in plants - translocation
- explain the process importance: water moves in from xylem, increases pressure allowing assimilates to move down pressure gradient from source to sink

4) formation of tissue fluid
- osmotic pressure and hydrostatic pressure
importance: tissue fluid supplies glucose, oxygen and amino acid to cells - allow respiration to take place as they are respiratory subrstrates

Question 4

importance of receptors in living organisms

Answer 4

1) control of blood glucose
- insulin, glucagon, adrenaline
- maintenance of stable blood glucose concentration
- importance: link to osmoregulation and ADH

2) control of heart rate
- baroreceptors ad chemoreceptors
- returning blood pressure and pH/Co2/O2 levels back to normal

3) nerve impulses
- synaptic transmission (acetylcholine receptors)
- neuromuscular junctions
off spec link: myasthenia gravis - autoimmune disorder - antibodies destroy acetylcholine recpetors at neuromuscular junction leading to muscle weakness

4) pacinian corpuscle
- process of stimulation leads to generator potential

Question 5

importance of bonds and bonding
NOT DONE

Answer 5

1) proteins
- primary,secondary and tertiary structure
- specific tertiary structure
- specifc enzymes

Question 6

The importance of concentration gradients in organimss

Answer 6

1) co transport of glucose
- sodium ions concentration gradient
- allows maximum absorption of glucose in small intestine
-

2) Reabsorption of water in the nephron
- loop of henle, counter current muliplier
- maintains sodium ion gradient in medulla
- ensures water leaves glomeluar filtrate, concentrating urine

3) synaptic transmission
- cholinergic recpetor
sodium volatge gated channels open
- depolarision of membarne allowing action potentials to be generated in postsynaptic neurones

4) photosynthesis
- LDR
- Chemiosmosis theory
- synthesis of ATP
importance - provides energy to reduce Gp to TP in LIR

Question 7

Importance of cycles in biology

Answer 7

1. cardiac cycle
   - explain the process
   importance: allows heartbeat and circulation of blood around the body, valves prevent backflow of blood
2. nitrogrn cycle
   - explain process
   allow nitrogen to be converted to nitrates that can be assimilated by plants for protein synthesis and growth
   eg amino acids
3. krebs cycle
   - explain the process importance
   - generates ATP and NADH and FADH for oxidartive phoisphorylation
4. ## calvin cycle