Biology Flashcards
4 factors affecting the rate of transport
Temperature
Concentration
Surface area to volume ratio
Diffusion distance
Eukaryotic
Has a nucleus
Prokaryotes
No nucleus
Magnification
Magnification = image size/ real size
Microscope practical
1- add onion cell to slide 2- add a drop of iodine 3- cover with a cover slip 4- put onto a stage 5- start with lowest magnification 6- focus it with the coarse focus knob 7- increase magnification 8- adjust focus with fine focus knob
Specialised cells examples
1- sperm cell 2- nerve cell 3- muscle cell 4- root hair cell 5- phloem and xylem cells
The cell cycle
1- cell grows
2- DNA replicated
3- mitosis
Stem cells
Cells that can become into any type of cell
Diffusion
The movement of particles from a high concentration to a low concentration across a concentration gradient
Osmosis
Movement of water molecules from an area of high concentration to an area of low concentration across a partially permeable membrane
Osmosis practical
1- add 5 pieces of potato cyclinders to 5 different concentration of sugars
2- measure mass before
3- take out the 5 pieces and measure mass
4- if the mass of the potato has increased then osmosis has occurred and the sugar solution is highly concentrated
5- calculate percentage change of mass
Active transport
Movement of particles from an area of low concentration to high concentration
REQUIRES ENERGY
Gas exchange in lungs
Oxyen into blood by diffusion
Carbon dioxide into lungs by diffusion
Villi helps with digestion
Villi has a large surface area so food is absorbed more quickly into the blood
What do enzymes need to work
Correct PH
right temperature
Enzyme practical
1- add iodine to every tile
2- add starch solution to a test tube
3- add amylase solution to a test tube
4- add buffer ph5 solution to a test tube
5- add all to a beaker and let them reach 30degrees
6- after 10 minutes mix all 3 tubes into one
7- add the test tube to the water bath and start a stopwatch
8- every 30 seconds take a drop and add to iodine
9- when the solution stops turning blue black then starch is no longer present
10- repeat for buffet ph 7 and 9
Rate of reaction formula
Rate=1000/time
Rate=amount/time
Amylase location
Salivary gland
Pancreas
Small intestine
Protease location
Stomach
Pancreas
Small intestine
Lipase location
Small intestine
Pancreas
Bile
Neutralises stomach acid and emulsifies fats
Test for sugars
Benedicts test
Turns green,yellow or brick red
Test of starch
Iodine solution
Turns blue black
Test for protein
Biuret solution
Turns pink or purple
