B1 KEY CONCEPTS Flashcards
What is magnification
The number of times bigger something appears under a microscope
What is the eyepiece lens
The lens on a microscope that you look through
What is the objective lens
The lens at the bottom of a microscope. There are normally three you can choose from
What is total magnification
Eyepiece lens x objective lens
What is resolution
The smallest distance between two points did so that they can still be seen as two separate points
What are stains
Dyes added to microscopes slides to show the details more clearly.
What’s a milli
Thousandth, 1x10-3
a millimetre is a thousandth of a metre
What is a micro
Millionth, 1x10-6
A micrometre is a millionth of a metre
What is a nano
Billionth, 1x10-9
A nanometre is a billionth if a metre
What is a pico
Trillionth, 1x10-12
A picometre is a trillionth of a metre
Cell
The basics structural unit of all living things (the building blocks of life)
Parts of an animal cell
Cell membrane Cytoplasm Nucleus Ribosomes Mitochondria Cell wall Permanent vacuole Chloroplasts
Parts of a plant cell
Cell membrane Cytoplasm Nucleus Ribosomes Mitochondria Cell wall Permanent vacuole Chloroplasts
Cell membrane
Controls what enters and leave the cell
Cytoplasm
A jelly like substance where chemical reactions take place
Nucleus
Contains DNA and controls the cell
Ribosomes
Produces protein
Mitochondria
Releases energy by aerobic respiration
Cell wall
Protects and supports the cell
Made of cellulose
Permanent vacuole
Store sap and helps to support the cell
Chloroplasts
Where photosynthesis happens
Contains chlorophyll
Micrograph
A picture produced by a microscope
Light microscopes
A microscope that uses light can magnify up to 1500 times
Electron microscope
A microscope that uses electrons to produce an image can magnify up to 1000000 times
Actual size of cell
Actual size= measured size: magnification
Convert mm to um
Micrometers (um) = millimetres (mm) x 1000
Small intestine
Job- to absorb small food molecules produced during digestion
Adaptations - tiny folds called microvilli that increase their surface area
Sperm cell
Job- fertilise an egg and deliver male DNA
Adaptations- a tail to swim mitochondria to give energy for swimming. An acrosome to break through the eggs jelly coat , haploid nucleus with only half the total DNA
Egg cell
Job- to be fertilised by a sperm and then develop an embryo
Adaptations- jelly coat to protect the cell many mitochondria and nutrients to provide energy for growth haploid nucleus with only half the total DNA
Ciliated epithelial cell
Job- to clear mucus out of your lungs
Adaptations- small hairs on the surface called cilia which wave to sweep mucus along
Parts of a bacterial cell
All bacteria - cell memebrane, cell wall , cytoplasm , ribosomes , chromosomal DNA , plasmid DNA
Some bacteria - flagellum
Chromosomal DNA
Large piece of DNA containing most genes
Plasmid DNA
Small loops of DNA containing a few genes
Flagellum
A tail used for movement
Eukaryotic cells
Cells with a nucleus
Prokaryotic cells
Cell without a nucleus
Digestion
Breaking large food molecules down into ones small enough to absorbed by the small instestine
Catalyst
A substance that speeds up a chemical reaction without being used up
Enzyme
A protein that works as a catalyst to speed up the reactions in our cells
Digestive enzymes
Enzymes that break large food molecules down into smaller ones
Amylase
Where found- saliva
Small intestine
What it does- breaks down starch into simple sugars such as maltose
Lipase
Where found - small intestine
What it does- breaks down proteins into amino acids
Protease
Where found- stomach
Small intestine
What it does- breaks down proteins into amino acids
Substrate
The chemicals that an enzyme works on
Active site
An area of an enzyme with the same shape as the substrate
Lock and key mechanism
The substrates moves into the active site and reacts to form the products
The products leave the active site do another substrate can then enter and so on
Specificity
Each enzyme can only work on one substrate because the shape of the active site to match
Denature
When the shape of the active site changes shape so the enzyme stops working
Optimum temperature
The temperature when an enzyme works fastest
Increasing the temperature
Increasing to optimum
Rate increases because particles move faster
Increasing past optimum
Rate decreases as enzyme denatures
Optimum pH
The pH when enzyme works fastest (around pH 6-8 for most human enzyme)
Changing pH
Rate decreases as you move away from the optimum because the enzyme denatures
Increasing substrate concentration
As first rate increases but then it levels out as the enzyme is working as fast as possible
Concentration
The number of particles In a given volume
Concentration gradient
The difference in concentration between neighbouring areas
Diffusion
The movement of particles from high to low concentration
Diffusion examples
Lungs- oxygen into blood carbon dioxide out of blood
Leaf-carbon dioxide into leaf oxygen out of leaf
Partially permeable membrane
A membrane that allows some molecules but not others to pass through it
Osmosis
The movement of water across a partially permeable membrane from high water/low solute conc to low water/high solute conc
Osmosis examples
Water into plant roots water in/out of any cells
Active transport
Using energy to move substances from low to high concentration
Active transport examples
Minerals being absorbed into plant roots
