Topic 1 - Cell biology (1) Flashcards
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What types of organism are there? (2)
- prokaryotes
- eukaryotes
What are all living things made of?
cells
What are the two types of cells?
- prokaryotic cells
- eukaryotic cells
What are two examples of eukaryotic cells?
Eukaryotic cells are complex and include plant and animal cells
Give an example of a prokaryotic cell?
- they are smaller and simpler like bacteria
What are eukaryotes?
organisms that are made up of eukaryotic cells
What is a prokaryote?
a prokaryotic cell (it’s a single celled organism)
What are the different parts of cells called?
subcellular structures (organelles)
What subcellular structures do most animal cells have? (5)
- nucleus
- cytoplasm
- cell membrane
- mitochondria
- ribosomes
What is the function of the nucleus?
contains genetic material that controls the activities of the cell
What is the function of the cytoplasm?
a gel like substance where most of the chemical reactions happen
(it contains enzymes that control these chemical reactions)
What is the function of the cell membrane?
holds the cell together and controls what goes in or out
What is the function of the mitochondria?
where most of the reactions for aerobic respiration take place (respiration transfers energy that the cells need to work)
What is the function of ribosomes?
where proteins are made in the cell (the site of protein sysnthesis)
What organelles are found in plant cells but not animal cells? (3)
- Rigid cell wall
- Permanent vacuole
- chloroplasts
What is the function of the rigid cell wall?
What is it made of?
supports and strengthens the cell
made of cellulose
What is the function of the chloroplasts?
What do they contain?
the site of photosynthesis (which makes food for the plant)
- they contain a green substance called chlorophyl (which absorbs the light needed for photosynthesis)
What is the function of the Permanent vacuole?
contains cell sap (a weak solution of sugar and salts)
REMEMBER:
the cells of algae (e.g. seaweed) also have a rigid cell wall and chloroplasts
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How do the size of bacteria cells (prokaryotic) compare to plant and animal cells (eukaryotic)?
Bacteria cells are much smaller
What type of organism are bacteria?
prokaryotes
TRUE OR FALSE:
Bacteria cells contain chloroplasts and mitochondria?
FALSE
What do bacterial cells have instead of a ‘true’ nucleus?
a single circular strand of DNA that floats freely in the cytoplasm (single DNA loop)
What are plasmids?
small rings of DNA
What subcellular structures can be found in bacteria cells? (5)
- cytoplasm
- cell membrane
- cell wall
- single DNA loop
(may also contain 1 or more plasmids)
What do we study cells with?
microscopes
What does it mean to magnify an image?
make it look bigger
How do light microscopes work and what do they let us see?
they use light and lenses to form an image of a specimen and magnify it
they let us see induvidual cells and large subcellular structures, like nuclei
How do electron microscopes work?
they use electrons (instead of light) to form an image
What is resolution?
the ability to distinguish between two points
(higher resolution gives a sharper image)
Why are electron microscopes better for studying cells? (3)
- they have a much higher magnification than light microscopes
- they have a higher resolution than light microscopes
- they let us see smaller things in more detail
What parts of cells can we see using an electron microscope?
- the internal structure of mitochondria and chloroplasts
- they let us see tinier things like ribosomes and plasmids
