B1: Cell Structure And Transport Flashcards
Function of the nucleus
Contains genetic material
Controls the activities of the cell
Cytoplasm
Most chemical processes happen here, controlled by enzymes
Cell membrane
Controls the movement of substances in and out of the cell
Mitochondria
Most energy is released by respiration here
Ribosomes
Protein synthesis happens here
Cell wall
Protects and strengthens the cell
Keeps its rigid structure
Chloroplasts
Contain chlorophyll to absorb light energy for photosynthesis
Permanent vacuole
Contains cell sap to keep cell turgid
Eukaryotic Cell Features
Always part of plant and animal cells
Larger than prokaryotic cells (10 - 100 micrometers)
Genetic material enclosed in a nucleus
Prokaryotic cell features
Always bacterial cells
Smaller than eukaryotic cells (0.1 - 5 micrometers)
Genetic material stored in small DNA loops called plasmids
Electron microscope features
High magnification (x1,000,000)
High resolution (0.2 micrometers/200 nanometers)
Expensive
Take up lots of space
Light microscope features
Low magnification (x400)
Low resolution (0.4 - 0.7 micrometers/400 - 700 nanometers)
Cheap
Easy to use
Nerve cell adaptations
Carry electrical impulses around the body of an animal for rapid communication
Long axons to carry information
Synapses to pass information to other cells
Lots of dendrites to make connections with other cells
Lots of mitochondria for energy
Sperm cell adaptations
Streamlines shape
Large nucleus containing lots of genetic material
Lots of mitochondria for energy
Has an acrosome containing enzymes to break through the egg for fertilisation
Muscle cell adaptations
Contract and relax to bring about movement
Store glycogen to be used in respiration
Contain lots of mitochondria to transfer energy for contracting and relaxing
Contain proteins that slide over one another
Root hair cell adaptations
Lots of mitochondria to transfer energy for active transport of mineral ions
Large permanent vacuole speeds up movement of water by osmosis
Large surface area for water to enter the cell
Palisade Cell Adaptations
Carries out photosynthesis
Permanent vacuole keeps cell rigid, leaf spread and stem supported
Contains chlorophyll filled chloroplasts to absorb maximum light energy
Regular shape so cells can be packed closely together
Phloem cell adaptations
Cell walls between cells break down to form sieve plates
Very few supporting structures
Supported by companion cells
Mitochondria of phloem provide energy to other cells
Xylem cell adaptations
Spirals and rings of lignin to make them very strong
Cells can die and form hollow tubes
Function of the phloem
Transports food around the plant
Function of the xylem
Transports water around the plant
Osmosis definition
Osmosis is the movement of water from a dilute Regino to a concentrated region across a partially permeable membrane (ppm)
Active transport definition
The movement of substances from a dilute area to a concentrated area against the concentration gradient, using energy
Diffusion definition
Diffusion is the movement of particles from an area of high concentration to low concentration until evenly spread
