(Original post by TX22)
carbon monoxide can lead to atherosclerosis and CHD. it really easy to learn.
emphysema, lung cancer normally caused by tar.
Tar relates to emphysema chronic bronchitis, and lung cancer
carbon monoxide, nictotine related to CHD
also diet like cholesterol, lipoproteins, high salt intake relates to CHD.
Don't worry, I know this stuff, sitting this for a third time
Stroke, are also caused by nicotine, as nicotine create blood clots and a blood clot to the brain causes a stroke. And carbon momoxide irreversibly combines with haemoglobin making less o2 availabe for the brain.
Also Lung cancer, caused by carciongens in the smoke --->uncontrolled cell growth ---> malignant tumour--->blocks air flow--->decreases gas exchange and leads to shortness of breath.
Nucleic acids: Information molecules that carry the instructions for life
Water: Support, transport, medium for metabolism
Structural differences between a-glucose and b-glucose
A-glucose = Below
B-glucose = Above
In a-glucose, the OH bond is below the the plane of the ring structure whereas in b-glucose, the OH bond is above the plane of the ring structure.
Two monosaccharides of a-glucose form a disaccharide called maltose.
Lots more a-glucose molecules forms a polysaccharide called amylose.
Starch: energy storage in plants
Amylose is present in starch.
It's a long, unbranched chain.
The angles of the glycosidic bonds cause amylose to coil.
This makes it more compact, making it a good storage molecule, as more substance can be put into a small space.
Starch is also made up of amylopectin.
This is a long, branched chain.
These branches allow enzymes to access the glycosidic bonds with ease so glucose can be released quickly.
Starch is also insoluble in water which is vital as it means it does not affect the water potential of the plant cell and cause water to enter by osmosis (which would cause the plant cell to swell)
Glycogen: energy-storage in animals
Similar structure to amylopectin.
Also made on a-glucose subunits.
Differs to amylopectic as it has MORE side brances.
This makes it even more compact than starch.
Same properties as starch in that it's insoluble in water and it's branches allow glucose to be released quickly.
Made of b-glucose which forms long, straight chains.
Hydrogen bonds form between the different cellulose chains to form macrofibrils.
Macrofibrils can criss-cross and run in all directions to give the wall even more strength.
Cellulose has great mechanical strength and structural support.
About comparing the structure and functions of collagen and haemoglobin.. I can compare their structures but what would you say for their functions? Just one line about how collagen is strong and supportive, a fibrous protein but haemoglobin is a globular transport? Or would you have to relate the structure to the function?
(Original post by ro.)
I've got neculeaic acids and immune system down now, but i dont understand anything on protein synthesis, like i don't even understand what it says in my revision guide on it.
And i understand smoking somewhat , but i just cant seem to remember it.
I'll explain protein synthesis to you if you want. What revision guide do you have?
Pretty much, think of protein synthesis in a step-by-step process like this: DNA --> RNA --> CYTOPLASM --> RIBOSOME --> PROTEIN.
DNA is found in the nucleus. To make a protein, it must first leave the nucleus. But, DNA is too large to move out of the nucleus. So, DNA copies itself into RNA, which is a smaller molecule (it has a single polypeptide chain, DNA has a double). RNA leaves the nucleus and joins with a ribosome in the cytoplasm. Ribosomes are the organelles that look like jelly babies and are the site where proteins are made. A protein is synthesised here. There you go! Any questions?
Just to add to that.. the DNA gives the RNA a sequence to follow. It puts all the free floating RNA nucleotides in the same order (as is on the DNA) so it's effectively a replicate (just single stranded so it's able to leave the nucleus)
After it's all in order, the RNA single strand will peel away from the DNA molecule and leave the nucleus via the nuclear pore as stated above. The ribosome's job is to translate the base sequences of RNA (which the DNA gave it) so the amino acids can be brought in the along in the correct order. Three bases code for an amino acid so a different order of bases will produce a different amino acid.
The amino acids undergo condensation reactions to join up.. forming peptide bonds.. the chain of amino acids produces a protein.
I suggest you watch a video of protein synthesis on youtube if you don't understand it. I find videos helpful for such subjects like DNA, RNA and immune response - just puts it all into context.