key concepts Flashcards
what are eukaryotic cells
complex cells which include all animal and plant cells
what are prokaryotic cells
smaller and simpler cells
bacteria cells
what are eukaryotes
organisms made up of eukaryotic cells
what is a prokaryote
a prokaryotic cells (single celled organism)
sub cellular structures of an animal cell
- nucleus
- cytoplasm
- cell membrane
- mitochondria
- ribosomes
sub cellular structures of plant cells
- nucleus
- cytoplasm
- cell membrane
- mitochondria
- ribosomes
- cell walls
- large vacuole
- chloroplasts
what is a nucleus
contains genetic material + controls the activities of the cell
what is a cytoplasm
gel like substance where most of the chemical reactions happen
what is a cell membrane
holds cell together and controls what goes in and out
what is mitochondria
where most of the reactions for respiration take place
what are ribosomes
these are involved in translations of genetic material in the synthesis of proteins
what is a cell wall
supports cell and strengthens it
what is a large vacuole
contains cell sap - solution of sugar and salts maintains the internal pressure to support cell
when are chloroplasts
these are where photosynthesis occurs which makes food for the plant. they contain and green substance called chlorophyll.
factors contained in bacterial cells
- chromosomal DNA
- ribosomes
- cell membrane
- plasmid DNA
- flagellum
what is flagellum
long hair-like structure that rotates to make the bacterium move. it can be used to move the bacteria away from harmful substances like toxins and towards things like oxygen
attributes of a egg cell
- contains nutrients in the cytoplasm to feed the embryo
- haploid nucleus
- after fertilisation it’s membrane changes to stop more sperm getting in
attributed of the sperm cell
- long tail to swim
- lots of mitochondria in the middle section
- has a acrosome at the front of the head where it stores enzymes to digest it’s way through the membrane of the egg cell
- haploid nucleus
what is a ciliated epithelial cells
lines the surface of organs to move substances in one direction along the surface of the tissue
e.g. move mucus through airways
total magnification equ
total magnification =
eye piece lens magnification x objective lens magnification
magnification equ
image size / real size
how to work with a microscope
- take a thin slice of your specimen, to let light through
- next take a clean slide and you are prepared to put one drop of water in the middle of it. This will secure the specimen in place.
- Add a drop of stain if your specimen is completely transparent or colourless this makes it easier to see
- Place a cover slip at one end of the specimen and carefully lower onto the slide, removing any air bubbles.
- Select the lowest powered objective lens.
- Use the adjustment knob to move the stage up set aside is just underneath the objective lens.
- Adjust the focus until you get a clear image.
how is a enzymes shape important
enzyme has an active site which only work with one substance, if it does not fit it won’t be catalysed.
this is called ‘lock & key’ mechanism fits together
what affects the rate of reaction and how
temperature - too high and it denatures
ph - to high or low interferes with the bonds holding the enzyme together
concentration - higher the concentration, faster the reaction.
how to calculate rate of reactions
1000/time
how to investigate ph effect on enzyme activity
- put a drop of iodine solution into every well of a spotting tile.
- Place a Bunsen burner on heatproof mat and a tripod and goes over the Bunsen burner put a beaker of water on top of the tripod and heat the water until 35°.
- Using a syringe at 3 cm³ of amylase solution into 1 cm³ of a buffer solution, with a pH of 5 to boiling tube. using test tube holders, put the boiling tube into a beaker of water and wait five minutes.
- Next use a different syringe to add 3 cm³ of starch solution to the boiling tube.
- Immediately mix the content of the boiling tube and start the stopwatch.
- Use continue sampling to record how long it takes for families to break down all of the starch.
- Repeat the whole experiment with a buffer solution of different pH values to see how pH affects the time.
