Biological Molecules Flashcards
what are the most common compounds of cells?
- water
- carbohydrates
- proteins
- lipids (fats)
- nucleic acids (DNA and RNA)
what are carbohydrates made from?
carbon, hydrogen and oxygen
what are carbohydrates used for?
- they are broken down in a chemical reaction, respiration, to release energy in the form of ATP
- this energy is used for other reactions and processes in cells
what are the smallest units of carbohydrates?
simple sugars e.g. glucose and fructose
what is an example of two sugar molecules joined together?
sucrose
what are some examples of complex carbohydrates?
- starch
- glycogen
what is the use of starch?
- used to store glucose in plants
what is the use of glycogen?
- used to store glucose in animals and fungi
why are starch and glycogen good storage molecules?
they are less soluble than simple sugars and so have less effect on water movement in and out of cells
what are lipids (fats) made out of?
carbon, hydrogen and oxygen
what are the functions of lipids?
- energy storage
- part of cell membranes
- thermal insulation
- electrical insulation (around nerve cells)
- buoyancy (helps marine animals such as whales to float)
what are lipids made of?
3 fatty acids and a glycerol molecule
what are proteins made out of?
carbon, hydrogen, oxygen and nitrogen
what are proteins made of?
many amino acids joined together
what does the shape of a protein do?
help the protein to carry out its job
