Cells And Simple Transport Flashcards
What are the parts of most human and animal cells?
Nucleus, cell membrane, cytoplasm, mitochondria, ribosomes
What is the function of
the nucleus?
Controls the cell activities
What is the function of
the cell membrane?
Controls the passage of substances into and out of the cell
What is the function of
the cytoplasm?
Where most reactions take place
What is the function of
ribosomes?
Where protein synthesis occurs
What is the function of
mitochondria?
Where most energy is released
during respiration
What is an organelle?
A part of a cell with a specific function.
What are the additional
parts of plant cells?
Permanent vacuole, chloroplasts,
cell wall
What is the function of
the cell wall?
Made of cellulose to strengthen the
plant and provide structure
What is the function of
chloroplasts?
Contain chlorophyll which absorb
light energy to make food during
photosynthesis
What is the function of
the permanent vacuole?
Filled with cell sap; pressure in
vacuole keeps cell turgid.
Bacterial cells consist of…
Cytoplasm, cell membrane, cell wall, small ring of DNA (plasmid); flagella for movement
What are eukaryotic cells?
Cells that have a nucleus (e.g. all plant and animal cells) packed with chromosomes.
What are prokaryotic cells?
Single celled organisms that do not contain a nucleus (e.g. bacteria). They are smaller than eukaryotic cells.
What is the average diameter of an animal cell?
10-30μm
What is the average length of a plant cell?
10-100μm
What is the average diameter
of a bacterial cell?
0.2-2μm
By which process do dissolved
substances move in and out of
cells?
Diffusion (moving from an area
of high concentration to low
concentration)
What affects the rate of
diffusion?
Concentration difference,
temperature, surface area of
the cell membrane
By which process does oxygen
diffuse into and out of cells?
Diffusion
How are sperm
cells adapted?
- Tail to help them swim.
- Large number of mitochondria in middle
section to release energy during
respiration for movement. - Acrosome stores digestive enzymes for
breaking down the outer layer of the
egg. - Large nucleus contains DNA to pass on.
How are nerve
cells adapted?
- Lots of dendrites to make connections to
other nerve cells. - Long axon to carry messages across
long distances. - Lots of mitochondria in nerve endings to
provide energy for production of
chemical messengers.
How are muscle
cells adapted?
- They contain special proteins that slide
over each other making the fibres
contract. - Contain many mitochondria to release
energy needed for chemical reactions
that take place as muscles contract and
relax. - Can store glycogen, a chemical that can
be broken down and used in respiration
to transfer energy needed for the fibres
to contract.
How are root hair
cells adapted?
- Large surface area for increased rate
of water uptake. - Large permanent vacuole with a high
concentration of nutrients to provide a
concentration gradient so it speeds up
movement of water by osmosis from
the soil across the root hair cell. - Many mitochondria that release
energy needed for active transport of
mineral ions into the root hair cells.
How are xylem cells
adapted?
- Form long hollow tubes that allow
water and mineral ions to move
through them. - Spirals and rings of lignin make them
very strong and help them withstand
the pressure of water moving up the
plant.
How are phloem
cells adapted?
- Contain sieve plates which allow
water carrying dissolved food to move
evenly up and down the tubes. - Are supported by companion cells
which contain a lot of mitochondria to
transfer energy needed to move
dissolved food up and down the cell.
How are
photosynthetic cells
adapted?
- Contain chlorophyll that trap light
needed for photosynthesis. - Positioned in continuous layers in
leaves and outer layer of stem. - Large permanent vacuole that keep
leaf spread out to increase the SA.
