Cells Flashcards
What do animal cells contain?
Nucleus
Cytoplasm
Cell Membrane
Mitochondria and Ribosomes
What do plant cells have, that animal cells do not?
Cell Wall
Permanent Vacuole
Chloroplasts
What does the nucleus do?
Contains genetic material that controls the activities of the cell
What does the cytoplasm do?
Gel-like substance where chemical reactions take place -
contains enzymes which control these chemical reactions
What does the cell membrane do?
Holds the cell together and controls what goes in and out
What does mitochondria do?
Produces energy from respiration
What do ribosomes do?
Make proteins (from amino acids)
What do cell walls do?
Supports and strengthens the cell (is made of cellulose)
What does the permanent vacuole do?
Contains cell sap (a weak solution of sugar and salts)
What do chloroplasts do?
Where photosynthesis occurs - they contain a green substance called chlorophyll
What are specialised cells?
Cells that are specialised for a specific function
How are sperms cells specialised?
1) Long tail - swim to the egg
2) Streamlined head - swim to the egg
3) Lots of mitochondria - provide energy
4) Enzymes in the head - digest through egg cell membrane
How are egg cells specialised?
1) Contains food reserves - to feed embryo
2) Membrane changes and prevents >1 sperm - right amount of DNA
How are palisade leaf cells specialised?
1) Lots of chloroplasts (near top of cell) - for photosynthesis
2) Large surface area - absorb more carbon dioxide from air
3) Thin shape - lots of them can be packed at the top of the leaf
How are red blood cells specialised?
1) Concave shape - big surface area for absorbing oxygen (and helps them pass smoothly through capillaries)
2) Lots of haemoglobin - pigment that absorbs oxygen
3) No nucleus - more space for haemoglobin
How are guard cells specialised?
1) Shape - opens/closes stomata (pores) in a leaf
2) Stomata opens - gases are exchanged for photosynthesis
3) Thin outer/Thick inner wall - opening/closing stomata
4) Sensitive to light - close at night
What are yeast and bacteria?
Single-Celled organisms
What is in a yeast cell?
Nucleus (containing genetic material)
Cell Wall
Cell Membrane
Cytoplasm
What is in a bacteria cell?
Genetic material
Cell wall
Cell membrane
Cytoplasm
What is diffusion?
Spreading out of particles from an area of high concentration to an area of low concentration
In what substances can diffusion occur?
Solutions and Gases
because their particles are free to move randomly
What affect does the concentration difference have on the diffusion rate?
The bigger the difference in concentration, the faster the diffusion rate.
How do dissolved substances move in and out of cells?
Diffusion
What are 4 molecules that diffuse through cell membrane?
Oxygen
Glucose
Amino Acids
Water
Why can’t some molecules diffuse through cell membrane?
Too big (starch and protein)
What is the net (overall) movement?
A movement from the side that has more particles
