B2.1 - Cell Structure Flashcards
what are all living organisms made of?
cells
what are the structures of cells in BOTH: animal and plant cells?
cell membrane, nucleus, cytoplasm and mitochondria.
what structure cannot be seen in a cells underneath a microscope?
mitochondria and ribosomes
what are the structures of a PLANT CELL?
cell wall, cell membrane, nucleus, cytoplasm, vacuole, chloroplasts and mitochondria.
what are the structures of an ANIMAL CELL?
cell membrane, nucleus, cytoplasm, mitochondria and ribosomes
describe the function of a cell wall
- tough layer made of cellulose
- surrounds the cell membrane
- freely permeable so it allows water and salt to pass through
- protects and surrounds the cells as well as prevents the cell from bursting
describe the function of a cell membrane
- inner layer which surrounds the cell
- partially permeable so it controls what substances enter or leave the cell
describe the function of a nucleus
- contains DNA in the form of chromosomes
- controls cell division, cell development and cell activities
describe the function of a cytoplasm
- it contains cell organelles
- chemical reactions take place here
- is jelly like and 70% water
describe the function of a mitochondria
- found in the cytoplasm and are tiny organelles
- responsible for producing energy from food substances through the process of aerobic respiration
describe the function of a vacuole
- it is a fluid filled space surrounded by a membrane
- it contains salts and sugars which is ‘ cell sap ‘
- it helps keep the plant turgid (firm)
describe the function of chloroplasts
- organelle which contains chlorophyll
- chlorophyll traps light energy for photosynthesis
describe the function of ribosomes
- produces, transports and stores proteins
- it looks like a group of flattened curves
what are the different specialised cells?
red blood cells root hair cells egg cell sperm cell palisade mesophyll cell ciliated cells
what is the structure and function of red blood cells?
structure:
- has no nucleus which gives extra space for oxygen
- has a biconcave shape which gives the cell a large surface area to volume ratio
function:
- transports oxygen around the body
what is the structure and function of root hair cells?
structure:
- has long projections which increases the surface area of the cell
- absorbs water through the process of osmosis
- large surface area increases the rate of absorption
function:
- absorbs water and mineral ions from the soil through the process of osmosis
what is the structure and function of palisade mesophyll cells?
structure:
- a type of plant cell
- have numerous chloroplasts
function:
- the numerous chloroplasts absorb light energy needed for photosynthesis.
what is the structure and function of ciliated cells?
structure:
- have small projections called cilia
- they have hair like structures
function:
- the tiny hair-like structures on the surface of the cell are used to sweep mucus and other bacteria in the trachea and bronchi sweeping it away from the lungs to the back of the throat where it can be swallowed
what is the structure and function of egg cells?
structure:
- they have a large amount of cytoplasm containing yolk droplets made up of fat and protein
- nucleus carries genetic information
function:
- house an embryo while it grows providing a lot of energy for growth from the large food store
- reproduction
what is the structure and function of sperm cells?
structure:
- The head of the sperm is shaped like an oval and it contains the nucleus which carries the genetic information
- The tip of the sperm is called an ‘acrosome’ which secretes enzymes to digest the cells around an egg and the egg membrane.
- The midpiece is packed with mitochondria to provide energy for movement
- The tail uses a whip-like action which enables the sperm to swim.
function:
- Reproduction achieved by fertilising the egg.
what is the equation for magnification?
MAGNIFICATION = MEASURED LENGTH (MM) / ACTUAL LENGTH (MM)
