Ch1 Cell structure and transport Flashcards
Plant cell structure
Cell membrane Cell wall Ribosomes Mitochondria Permanent vacuole Chloroplasts Nucleus Cytoplasms
Animal cell structure
Cell membrane Ribosomes Mitochondria Cytoplasm Nucleus
Cell membrane
Controls the movement of substances in and out of the cell
Cytoplasm
Where chemical reactions take place
Cell wall
Contains cellulose
Supports and strengthens cell
Eukaryotic
Plant cells
Animals cells
Fungi
Protista
Prokaryotic
bacteria
Permanent vacuole
Filled with cell sap
Keeps cell rigid to support plant
Mitochondria
Where respiration takes place
Chloroplasts
Contains green substance chlorophyll
Is where photosynthesis takes place
Nucleus
Contains genetic info
Controls activities of the cell
Ribosomes
Where protein synthesis takes place
Bacteria Cell structure
cytoplasm flagella plasmids genetic string cell wall cell membrane slime capsule
flagella
long protein strand that moves the bacteria cell
plasmids
small rings of dna that code for specific features
Nerve cell function
Carry electrical
impulses around body
3 Nerve cell adaptations
lots of dendrites to make connections
an axon that carries nerve impulses from one place to another
lots of mitochondria to provide energy needed to make transmitter chemicals
Muscle cell function
Contract and relax to move bones of skeleton
Striated muscle cell adaptation
contain special proteins that slide over each other making fibres contact
contain many mitochondria to transfer energy needed for chemical reactions for movement
can store glycogen
Sperm cell function
move through the female reproduction system to fertilise an egg
Sperm cell adaptations
Long tail to help move the sperm
Middles section full of mitochondria, to transfer energy needed for tail to move
acrosome stores digestive enzymes for breaking down outer layers of eggs
large nucleus containing genetic info from the male
streamlined head
Root hair cell function
Take up water via osmosis and mineral ions from soil via active transport
Root hair cell adaptations
large SA
large permanent vacuole that speeds up movement of water via osmosis
Many mitochondria that transfer energy needed for active transport of mineral ions
Xylem cell function
Transport tissue that carries water and mineral ions from roots to leaves.
Supports the plant
Xylem cell adaptations
Chemical lignin builds up in spirals in cell walls, killing xylem cells to form long hollow tubes so water can move through easily
Spirals and rings of lignin makes cells strong enough to withstand pressure of water movement and help support the plant
Phloem cell function
Transport tissue that carries dissolved foods up and down plant
Phloem cells adaptations
Special sieve plates formed from cell walls allow water carrying food to move up and down
Supported by companion cells that transfer energy needed to move dissolved food up and down plant
Diffusion
Net movement of particles form an area of high concentrations to low concentration(down the concentration gradient)
Factors affecting diffusion rate
steepness of concentration gradient
the temperature
large SA
length of diffusion path
Osmosis
Net movement of water molecules across a partially permeable me range from a dilute solution to a concentrated solution
Hypertonic
Solute Concentration of external> Solute Concentration of internal
Isotonic
Solute Concentration of external= Solute Concentration of internal
Hypotonic
Solute Concentration of external< Solute Concentration of internal
Plant osmosis
need fluid surrounding cells to be hypotonic to cytoplasm(turgid)
Plasmolysis
If water is lost by osmosis, the vacuole and cytoplasm shrink, cell membrane pulls away from cell wall and plant cell dies
Active transport
Substance moves against concentration gradient( lower to higher)
Energy is required
Examples of active transport
Absorption of mineral ions from soil into root hair cells
Glucose absorbed out of gut and kidney tubules into the blood
Adaptions for exchange surfaces
large SA
thin membrane to provide short diffusion path
efficient blood supply moves diffusing substances away from exchange surfaces and maintains steep concentration gradient
ventilation to make gas exchange more efficient by maintaining steep concentration gradient
electron microscope advantages
higher magnification
higher resolving power
magnification
size of image/ size of object
