key concepts in biology Flashcards
what type of cell is a bacterial cell?
prokaryotic
what type of cells are animal and plant cells?
eukaryotic
what things are in both plant and animal cells and what are their functions?
- nucleus: contains cells dna
- cytoplasm: where chemical reactions take place
- cell membrane: controls what enters and leaves the cell
- mitochondria: where respiration occurs
- ribosomes: where protein synthesis occurs
what other things are only in plant cells and what are their functions?
- chloroplasts: where photosynthesis happens
- vacuole: contains cell sap
- cell wall: provides the cell with strength
which 6 things are found in a bacterial cell and what are their functions?
- cytoplasm: where chemical reactions take place
- cell membrane: controls what enters and leaves the cell
- cell wall: provides structure
- chromosomal dna: floats in cytoplasm due to no nucleus
- plasmids: rings of dna
- flagella: tail used for movement
what do cells specialise through?
differentiation
what are the 3 types of specialised cells in animals?
- sperm cell: carries male dna to the egg cell for reproduction
- egg cell: binds with sperm cell to develop into an embryo
- ciliated epithelial cell: traps mucus from going into the stomach
what are the 3 types of specialised cells in plants?
- root hair cells: take up water by osmosis and mineral ions by active transport from the soil
- xylem cells: transport water and mineral ions up the plant from the roots to the shoots
- phloem cells: carry products of photosynthesis to all parts of the plants
what is the difference between light microscope and electron microscopes?
light microscope: use light to view things, cannot view living cells
electron microscope: uses electrons to view things, can view living cells and very small bacterias
when placed magnifications on each other, which one always goes on the objective lens?
the bigger number
what is the equation for magnification?
image size= actual size x magnification
what are the units for?:
- centimetres:
- millimetres:
- micrometres:
- nanometres:
- centimetres: 1x10^-2
- millimetres: 1x10^-3
- micrometres: 1x10^-6
- nanometres: 1x10^-9
how do you prepare a microscope slide?
- take off a thin layer the sample
- add a stain (iodine) to make it more visible
- put them on the slide
- place a cover slip on top
what are enzymes?
biological catalysts that speed up a reaction without being used up
how do enzymes work?
the substrate fits onto the active site of an enzyme making an enzyme substrate complex which leads to the making of products
how does temperature affect the enzyme activity?
when the temperature is too low, the enzyme activity is low due to not enough energy
when the temperature gets higher, the enzyme activity reaches the optimum (the best)
when the temperature gets too hot, enzyme activity decreases as the enzyme has denatured
how does pH affect enzyme activity?
if the pH is too low or too high the enzyme activity decreases because the enzyme has denatured
if the pH reaches the optimum the enzyme activity is at its best
how does substrate concentration affect enzyme activity?
as the substrate concentration increases the enzyme activity also increases but soon it stops increasing due to the active site being filled up
how do you calculate the rate of a reaction?
rate of reaction= change/time
what do lipase break down to produce?
lipase break down fats into fatty acids/glycerol
what does protease break down to produce?
protease breaks down proteins into amino acids
what does amylase break down to produce?
amylase breaks down starch into sugars
what is the test for starch?
add iodine, if present it will go from orange to blue/black
what is the test for reducing sugars?
add benedicts solution and heat for 2 minutes, if present it goes red
