Card Set Information
Biology Investigating Cells
Standard Grade Biology - Investigating Cells
Why are stains used?
To make cell structures more clearly visible
the building blocks of life
All living things are made up of ____?
A living thing is called an ________?
Animal cells have.....?
Plant cells have.....?
What is the function of the cell membrane?
Controls what goes in and out of the cell
What is the function of the nucleus?
Controls the cell
What is the function of the cell wall?
Protects and supports the cell
What happens in the cytoplasm?
What does the vacuole do?
Holds spare water
Green plants contain chlorophyll in the chloroplasts which ______ the suns energy?
What is diffusion?
Diffusion is the movement of molecules from an area of high concentration to an area of low concentration
Once the molecules have spread out the have reached _______?
The greater the concentration gradient the ________ the rate of diffusion?
The larger the molecule the _______ the rate of diffusion?
Diffusion can occur in....?
air and liquids
Oygen and food diffuse ______ the blood then the cells of the body?
Carbon dioxide diffuses _____ the cells into the blood, to the lungs to be breathed out of the body?
The cell membrane controls movement into and out of the cell - it is......?
What is osmosis?
The movement of water molecules from a high to a low water concentration through a selectively permeable membrane
When water moves
a plant cell it becomes ______?
When water moves
a plant cell it is said to be _______?
When the cytoplasm shrinks and the cell membrane starts to peel away from the cell wall, the cell has undergone _________?
What is a concentration gradient?
The difference between a high and a low concentration
Cell division ______ the number of cells in an organism?
Single-celled organisms reproduce by ______?
Mitosis (nuclear division) and cell division are important for......?
growth and repair
Describe the stages of mitosis
1. The chromosmes become visible in the nucleus
2. The number of chromosomes double
3. The chromosmes line up along the equator (the centre of the nucleus)
4. Spindle fibres attatch to the chromosmes
5. The chromosomes are pulled apart (towards the poles)
6. The cytoplasm divides
7. The cell membrane divides and two new cells are formed
8. The nucleus reforms
What is the centre of a chromosome called?
A "normal" human should have ____ chromosomes?
46 (2 sets of 23)
Human cells with 46 chromosomes are called _______?
biological catalysts which speed up reactions
Enzymes work on ______?
Enzymes are made from ______?
Enzymes are _______ in a reaction?
never used up
Ezymes are _______ - they only act on one type of substrate?
Over 50 degrees celcius ezymes are _______?
The temperature enzymes work best at is their ______ temperature?
What is pepsins optimum pH?
What is catalase's optimum pH?
What enzyme builds up glucose-1-phosphate into starch?
What enzyme speeds up the breakdown of hydrogen peroxide into oxygen and water?
What enzyme breaks down starch into maltose?
What food group contains the most energy per gram?
fats and oils
What is the word equation for aerobic respiration?
glucose + oxygen ----> energy + carbon dioxide + water
_______ energy is released from cells during respiration?
What is energy from respiration needed for?