B2.1 Cells and simple cell transport Flashcards
What are all living things made up of?
Cells
What is an animal cell made up of?
- Nucleus
- Cytoplasm
- Cell membrane
- Ribosomes
- Mitochondria
What is the nucleus?
The genetic material which controls the activities of all cells
What is the cytoplasm?
Jelly-like substance containing all of the cell’s organelles, most cellular processes occur there.
What is the cell membrane?
A partially permeable barrier regulating the substances which enter and leave the cell.
What are the mitochondria?
The site of respiration where energy is released.
What are the ribosomes?
The site of protein synthesis
What parts does a plant cell have in addition to an animal cell?
- Cell wall
- Chloroplasts
- Permanent vacuole
What is the cell wall?
A rigid external coat made up of cellulose supporting the plant cell
Why don’t animal cells need a cell wall?
They have a skeleton which does the job
What is the permanent vacuole?
A cell sap filled cavity containing water and nutrients
What are the chloroplasts?
Sites of photosynthesis
What pigment do chloroplasts contain?
Chlorophyll
What is a yeast cell?
A single celled fungus
What is a yeast cell made up of?
- Cell wall
- Cell membrane
- Nucleus
- Cytoplasm
What are two uses of yeast?
- Making bread (using aerobic respiration)
- Fermentation (using anaerobic respiration - glucose —> carbon dioxide + ethanol)
What is a bacterium cell made up of?
- Cell wall
- Cell membrane
- Cytoplasm
- Strands of genetic material (no nucleus)
What are two uses of bacteria?
- Making cheese
- Making yoghurt
What are the adaptations of a fat cell for its function? (3)
- Little cytoplasm (more room for fat)
- Little mitochondria (they use little energy)
- They can expand x1000 (more room for fat)
What are the adaptations of a sperm cell? (3)
- Long tails (to swim to the egg cell)
- Middle full of mitochondria (more energy to swim)
- Head full of acrosome (stores digestive enzymes to break down egg cell)
What are the adaptations of a palisade cell? (4)
- Packed with chloroplasts
- Chloroplasts closer to the top of the cell
- Thin shape (more of them can fit at the top of the leaf)
- Tall shape (more surface area on the side - more CO2 absorbed)
What are the adaptations of a guard cell? (5)
- Special kidney shape which opens and closes stomata
- Lots of water = guard cells go plump and turgid, opening stomata
- Small amount of water = guard cells go flaccid, closing stomata
- Thin outer walls and thickened inner walls make this work
- Sensitive to light, they close at night (no photosynthesis happening)
What are the adaptations of a red blood cell?
- Biconcave shape - large surface area for oxygen, easy to pass through capillaries
- Full of haemoglobin
- No nucleus - more space for haemoglobin
What is haemoglobin?
A pigment which absorbs oxygen
What is diffusion?
The net movement of particles from an area of high concentration to an area of low concentration
The bigger the difference in concentration between two areas, the —— the diffusion rate.
Faster
What must particles diffuse across in body cells?
The cell membrane
What can diffuse across the cell membrane and why?
Only small molecules (e.g oxygen and glucose needed for respiration, amino acids and water) Bigger molecules (e.g starch and proteins) can't fit through the membrane.
Describe how diffusion occurs in body cells.
Useful particles move from the blood (where there is a lot of them) to the cell (where there isn’t a lot of them)
What physical state can diffusion occur in?
Liquids and gases
