Organic and inorganic compounds found in cells and their uses in cells

alternate title: but first, before day 1 of the 10daymemething, is biology

I present to you various garbled Bio notes from 8.3, i.e. Patterns in Nature, i.e. the gigantic chem-like hideous topic which is actually interesting once I start reading/making notes properly but by the time I've convinced myself to do that, I'm running out of time fffffffff anyway--

oh and DISCLAIMER: heed these at your own risk for I've no idea if they're 100% correct (:
they're just... mainly... you know, occasionally-note-assisted regurgitaton for my own memory/desperatepre-examcramming

 

1. Organic compounds in cells. Organice = synthesised by living things; contains carbon combined with hydrogen

CARBOHYDRATES
Made of carbon, oxygen and hydrogen
e.g. sugars, starch, glycerol
Sugars provide a form of quick energy to the cell
Sugar (in the form of glucose) is a reactant in aerobic cellular respiration, which produces ATP
Starch and glycerol are forms of stored energy
Cellulose is a structural part of cell walls

PROTEINS
Contain carbon, hydrogen, oxygen, nitrogen and sometimes phosphorous and sulfur
Made up of long chains of amino acids joined by peptide bonds; long chains = polypeptides
Sequence of amino acids determines what kind of protein is formed
Proteins are used by the cell in growth and repair
Form an important structural component, e.g. in cell membrane and cytoskeleton
As enzymes, proteins control all metabolic reactions within cells

LIPIDS
Contains carbon, hydrogen and a small amount of oxygen
One glycerol to which fatty acids are joined
Store large amounts of energy (in the form of fat) - important biological fuel
Major structural component of all membranes in cells

NUCLEIC ACIDS
Made up of long chains of nucleotides
Nucleotide = ribose or deoxyribose sugar + nitrogen base + phosphate
DNA stores the info that controls all the activities of the cell; it also contains the hereditary info that is passed through generations in reproduction, etc.
RNA is used by ribosomes in protein synthesis, and it also does other stuff . . . I think . . . yeah . . .

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2. Inorganic molecules do not contain carbon combined with hydrogen and they do not form long chains.

WATER
Water forms 90% of the protoplasm (which is the entirety of the cell)
It is a transport medium
It is the medium in which all chemical reactions in cells take place
It can be used to regulate temperature in organisms
Can be a reactant in reactions

MINERAL SALTS
Chlorides, carbonates of sodium, phosphates, nitrates, etceteraaaaa
Dissolved as ions in the cytoplasm and in the vacuoles of plant cells
Used in the synthesis of macromolecules and body tissues (iron in blood, calcium in bones/teeth)
Assist in chemical reactions by helping enzymes to function
Assist in water balance
Essential for functioning of cell membrane and nerve+muscle cells

[some] GASES
Carbon dioxide + oxygen
Dissolved in the protoplams
Used and/or produced in chloroplasts and mitochondria
Carbon dioxide is a reactant in photosynthesis and a product of aerobic cellular respiration
Carbon dioxide can also react with water to form biocarbonates, a buffer limiting changes in cells' pH
Oxygen is a product of photosynthesis and a reactant in aerobic cellular respiration



...yeah once again you see that I have this disturbing/stupid penchant to like to go into unncessary detail. What are the chances that we'll need to know that carbon dioxide reacts with water to form a bicarbonate that helps regulate acidity/alkalinity levels in cells? Or that mineral salts are essential in the functioning muscle and nerve cells?

Need to remember:
carbohydrates in the form of sugars provide a quick source of energy for the cell
carbohydrates in the form of starch and glycerol are forms of stored energy