B1: Cells And Organisation Flashcards
What is diffusion?
When particles move from an area of high concentration to an area of low concentration
What are examples of diffusion in everyday life?
When water is mixed with juice
When a lynx can is sprayed
Is energy needed for diffusion to happen?
No because it is a passive process
What is a concentration gradient?
The difference in concentration between two areas
What happens to the rate of diffusion if the concentration gradient is steeper?
The rate of diffusion is faster
What is Osmosis?
The movement of particles from a dilute solution (high concentration of water) to a more concentrated solution (less concentration of water) across a partially permeable membrane
What are partially permable membranes?
Membranes that only let certain molecules through
Why is osmosis important in plants?
Plants rely on the movement of water to survive
If a cell is turgid what does it mean?
The cell is very strong and not flimsy
If a cell is flaccid what does that mean?
It is flimsy and not very firm
What is active transport?
When particles move up (or against) a concentration gradient using energy
Is energy needed for active transport?
Yes
In active transport do the particles go from high to low concentration or low to high concentration?
Low to high concentration
When particles are using active transport to enter a cell, what must they pass through using active transport?
The cell membrane
How do you figure out the real size of something in a magnified image?
You work out the image size after magnification using a ruler
You then divide the image size by the magnification
e.g
Image size = 10
Magnification = 50
10/50 = 0.2mm
0.2mm = real size
What features do plant cells have that animal cells do not?
Cell Wall
Chloroplasts
Permanent Vacuole
What does the cell membrane do?
Controls which substances pass in and out of the cell
What does the nucleus do?
Contains genetic material (DNA)
What does the cytoplasm do?
It is where chemical reactions take place
What does the mitrochondria do?
Provide cells with the energy they need to function
What does the ribosome do?
It is the site of protein synthesis
What does the cell wall do?
Supports and structures the cell
What does the chloroplast do?
It is where photosynthesis takes place
What does the permanent vacuole do?
Contains sell sap (mixture of sugars, salts and water) to help keep the cell turgid
What are 2 things different about a prokaryotic and a eukaryotic cell?
- Prokaryotic cells contain plasmids, eukaryotic cells do not
- Eukaryotic cells contain a nucleus, prokaryotic cells do not
What is the equation triangle linking magnification, real size and image size?
Real size on the top
Magnification and image size on the bottom
