Cells And Transport Flashcards
Function of cytoplasm
Liquid gel in which most of the chemical reactions take place
Function of nucleus
Control centre of cell, contains genetic information
Cell membrane function
Semi-permeable controls movement of material in and out of cell
Cell wall function
Support & protection of plant cell
Mitochondria function
‘Powerhouse’ of the cell (produces ATP by respiration)
Ribosomes function
Production of proteins
Chloroplasts function
Uses energy to make food by photosynthesis
Vacuole function
A space in the cytoplasm filled with cell sap that helps to keep the cell rigid
Stores food, water & waste in plants
Lysosomes function
Special type of vacuole that breaks down old cell parts and large molecules
ER function
Transport of chemicals and proteins within cells
Golgi function
Modifies proteins to make them functional
Transports proteins within cells
Cytoskeleton function
Support structure within cells (skeleton)
Made of proteins
Organ
Collection of tissues that perform a specific function within an organism
Organism
A living being
Organelle
A functional structure within a cell
Organ systems
Collection of organs that perform a specific function within an organism
Tissue
Collection of connected cells that perform a similar function within an organism
Cell
The structural unit of an organism may exist as independent life
Nerve cell function
Transmits nervous stimuli
Nerve cell adaption 3
- synapses & neurotransmitters
- can be very long
- myelin sheath (insulation)
Ciliated cell function
Clear airways
Ciliated cell adaption
Cilia that beat back & forward to move material
Sperm function
Fertilisation of egg
Sperm adaption 4
- small with tail for movement
- lots of mitochondria
- acrosome with special enzymes to digest egg membrane
- genetic information (23 chromosomes)
Egg function
Fertilisation
Egg adaption 3
- large and bulky
- contains yolk (food storage) for developing embryo
- genetic information (23 chromosomes)
Red blood cell function
Transport oxygen
Red blood cell adaption 2
- contains haemoglobin which binds oxygen
- no nucleus (more space for haemoglobin)
White blood cell function
Destroys pathogens
White blood cell adaption 2
- some produce antioxidants
- some have flexible cytoskeletons so that they can change shape quickly to engulf bacteria
Muscle cell function
Contraction
Muscle cell adaption 2
- long & flexible
- lots of mitochondria
Fat cell function
Store fat (source of energy)
Fat cell adaption 3
- little cytoplasm: lots of fat storage space
- few mitochondria
- can expand (up to 1000x)
Rods & cones function
Photoreception
Vision
Rods & cones adaptions 3
- contains visual pigment that detects light
- many mitochondria
- synapse that transmits signals into optic nerve
Skin cell function
Protection & heat regulation
Skin cell adaption 2
- pigments to absorb UV
- hair for insulation
Palisade cell function
Photosynthesis
Palisade cell adaption 3
Lots of chloroplasts
Tightly packed
elongated
Root hair cell function
Uptake of water and minerals
Root hair cell adaption 3
- have root hairs ( increases surface area)
- large permanent vacuole
- close to xylem (water transport)
Guard cell function
Control opening of stomata
Guard cell adaptions 2
- take up & release water by osmosis to open & close stomata
- thickened cell wall
Diffusion
The movement of gases or dissolved molecules from an area with a high concentration to an area with a low concentration
=the movement of molecules down a concentration gradient
How does concentration gradient affect the rate of diffusion
The steeper the concentration gradient, the faster the rate of diffusion
How does diffusion distance affect the rate of diffusion
The shorter the diffusion distance, the faster the rate of diffusion
How does surface area affect the rate of diffusion
The greater the surface area, the faster the rate of diffusion
How does temperature affect the rate of diffusion
The higher the temperature, the greater the rate of diffusion
How does size affect the rate of diffusion
The bigger something is, the longer it takes for something to diffuse to the centre
When is a large SA/V ratio good 3
- Organisms in hot climates need a large SA/V ratio so they lose heat quicker
- take up useful molecules
- get rid of waste products
W
When is a small SA/V ratio good
Organisms in cold climates need a small SA/V ratio so they can retain heat
Osmosis
The movement of water molecules from an area of high water concentration to an area of low water concentration across a selectively permeable membrane
Isotonic
Isotonic solutions have equal osmatic pressure
Hypotonic
Having a lesser osmatic pressure in a fluid compared to another fluid eg. Hypotonic solution
Hypertonic
Having a higher osmatic pressure in a fluid compared to another fluid
The carbohydrate stored in animal cells
Glycogen
What happens to animal cells inside a solution with very high sugar concentration
Water passes out of the cell by osmosis and cell shrinks and becomes flaccid
What happens to animal cells inside a solution with a very low sugar concentration?
Water diffuses into the cell making it swell up
Possible for cell to burst
How does water move into and out of living cells
By osmosis
What happens to plant cells inside a solution with a very high sugar concentration 1 word answer
Cell becomes plasmolysed
Plant cells inside a solution with a very low sugar concentration 1 word answer
Cell becomes turgid
Facilitated diffusion
The movement of a molecule from an area of high concentration to an area of lower concentration, with the help of a protein channel or carrier
Passive transport
The movement of molecules through cell membranes without the use of energy by the cell
(Eg diffusion, osmosis, facilitated diffusion)
Active transport across membranes
The movement of water molecules through cell membranes AGAINST a concentration gradient at the cost of energy and with the help of a carrier protein
Where does the energy for active transport come from
From respiration and is stored in the form ATP
How and why would a plant root cell be different from a plant leaf cell?
The plant root cell would not contain any chloroplasts because the roots are underground, don’t get any light & don’t carry out photosynthesis, so they don’t need chlorophyll
What is meant by the net movement of particles?
Movement of particles in - movement of particles out
What factors most affect the rate of diffusion in a liquid or a gas?
Temperature, concentration, available surface area
How can the number of mitochondria in a cell help you decide its function?
The number of mitochondria in a cell reflects the amount if energy needed by the cell, so a cell with many mitochondria will tend to be a very active cell, either dividing, contracting, or producing chemicals such as hormones or enzymes
Difference between animal and plant cells carbohydrate storage
Animals store carbohydrate as glycogen
Plants store carbohydrate as starch or sucrose
Suggest how the active transport of glucose out of the cell and into the blood stream helps with the absorption of glucose from the small intestine
As the glucose moves out of the cell, the concentration inside the cell decreases and increases the concentration gradient for diffusion of glucose into the cell
