key concepts in bio Flashcards
how do you calculate magnification
size of image/actual size
what is the magnification of a light microscope and an electron microscope
light = x2000 electron = x50million
what is the role of cytoplasm
site of most chemical reactions and activities
what are the sub-cellular structures found in a plant cell but not an animal cell
chloroplast, cell wall, vacuole
what is mitochondria
site of respiration
what is a eukaryotic cell
a cell with a nucleus
what is a vacuole
stores cell sap and helps to keep the cell firm
how big are eukaryotic cells and prokaryotic cells
e = 10-100 micrometres p = 0.1-5 micrometres
whats the difference between prokaryotic cells and eukaryotic cells
eukaryotic cells are bigger and found in plants, animals, fungi and protists, prokaryotic cells are bacteria
prokaryotic do not have a nucleus or chromosomes
what does it mean to be a haploid cell
to have just one set of chromosomes
what’s the role of the acrosome in the sperm cell
it contains an enzyme to penetrate into the egg cell
what is the middle section of the sperm cell filled with
mitochondria for energy
what is a zygote
a fertilised egg cell that results from the female and male gametes uniting
how has the egg cell’s cell membrane adapted to its function
it is adapted to change structure once a sperm cell has fertilised it so that no more sperms get into the cell
what does the cilia in ciliated epithelia cells do
they waft mucus to the back of the throat
what is a prokaryotic cell
a cell without a nucleus or chromosomes, bacteria is prokaryotic and it has one loop of chromosomal dna plus smaller dna loops called plasmids
where do you find stem cells in plants
meristem
what makes up carbohydrates, proteins and lipids
glucose, amino acids and fatty acids
what can enzymes also be called
biological catalysts (speeding up breakdowns and synthesis reactions) synthesis is when larger molecules are made from smaller molecules
what is the substrate of amylase, protease and lipase
a = starch (to glucose) p = proteins (to amino acids) l = lipids (to fatty acids and glycerol)
what is the lock and key theory
that a specific substrate will only fit the active site of a specific enzyme
what three things affect the rate of enzyme reaction
temperature, pH, substrate concentration (this will increase the rate until there are enough substrates to fill all of the enzymes so more substrates will make no difference)
what is used to measure the amount of energy in food
a calorimeter
what colour does iodine turn when there is starch present
blue-black
