When cells respire, they produce CO2, and so raise the ppCO2.
This increases the rate of oxygen unloading.
The saturation of blood with oxygen is lower, so more oxygen is released.
This is called the Bohr Effect.
Haemoglobin is different in different animals.
Organisms in environments with low oxygen concentration have haemoglobin with a higher affinity for oxygen.
This results in a dissociation cure to the left.
Active organisms with a higher oxygen demand have haemoglobin with a lower affinity for oxygen.
This results in a dissociation curve to the right.
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Variation In Carbohydrates & Cell Structure
Carbohydrates are made from monosaccharides.
Condensation reactions join monosaccharides together, and release water.
Glycosidic bonds join sugars together.
Plants store excess glucose as starch.
Starch is made from 2 alpha glucoses:
Amylose: Long, unbranched chain of alpha glucose. It has a coiled structure and is compact, so good for storage.
Amylopectin: Long, branched chain of alpha glucose. It's side branches allow enzymes to quickly break down the glycosidic bonds, so glucose is released quickly.
Starch is insoluble, so there is no osmosis.
Animals store excess glucose as glycogen, which is also an alpha glucose.
It has lots of side branches, so stored glucose is released quickly.
Glycogen is compact, and so good for storage.
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Variation In Carbohydrates & Cell Structure
Cellulose is long, unbranched chains of beta glucose.
There are straight bonds between the sugars, so the chains are strong.
The chains are linked by hydrogen bonds, forming strong microfibrils.
These microfibrils allow cellulose to provide structural support for the cells.
SIMILARITIES & DIFFERENCES IN PLANT & ANIMAL CELLS.
Similarities:
Plasma Membrane: Controls what goes in and out of cells.
Cytoplasm: Contains enzymes. Chemical reactions happen here.
Nucleus: Contains genetic material.
Mitochondria: Produces ATP for respiration.
Ribosomes: Protein synthesis.
Differences - Plant Cells have:
Cell Wall: Made of cellulose, it supports the cell.
Vacuole: Contains cell sap.
Chloroplasts: Where photosynthesis occurs.
They are surrounded by a double membrane.
They contain thylakoid membranes which stack to form grana.
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