Diffusion is the movement of particles from an area of high concentration to an area of low concentration.
Osmosis is the movement of water molecules from an area of high concentration of water molecules to an area of low concentration of water molecules through a partially permeable membrane
How is active transport different from osmosis and diffusion?
it is an active process
it goes against the concentration gradient
What is active transport?
It is an active process
the movement of substances from an area of low concentration to an area of high concentration against the concentration gradient
uses energy from respiration
involves a protein in the cell membrane
What do you find in an animal cell?
nucleus
cell membrane
mitochondria
ribosomes
cytoplasm
What do you find in a plant cell?
Cell membrane
cytoplasm
cell wall
vacuole
chloroplasts
mitochondria
nucleus
ribosomes
Plant features:
multicellular
have chloroplasts meaning they can photosynthesise
Their cells have cell walls made from cellulose
they store carbohydrates as sucrose or starch
Animal cell features:
multicellular
cant photosynthesise and don’t have chloroplasts
their cells don’t have cell walls
have nervous coordination meaning they can respond rapidly to changes in their environment
can move from one place to another
store carbohydrate in the form of glycogen
Fungi
Some are single-celled
Others have a body called a mycelium, which is made up of hyphae (thread-like structures)
Hyphae contain lots of nuclei
Can't photosynthesise
Cells have cell walls made of chitin
Most feed by saprotrophic nutrition - they secrete extracellular enzymes into the area outside their body to dissolve their food, so they can then absorb the nutrients
Can store carbohydrate as glycogen
Examples of fungi: yeast or Mucor
Protoctists:
Single Celled and microscopic
some have chloroplasts and are similar to plant cells
others are more like animal cells
protoctists examples:
chlorella or Amoeba
Bacteria:
single Celled and microscopic
don't have a nucleus
have A circular chromosome of DNA
some can photosynthesise
feed off other organisms, both living and dead
Viruses
smaller than bacteria, particles rather than cells
can only reproduce inside living cells
a virus is a parasite- depends on another organism to grow and reproduce
infect all types of living organism
come in different shapes and sizes
dont have a cellular structure - have a protein coat around some genetic material
Example of a virus: Influenz, HIV
Pathogens are organisms that cause disease. They include some fungi, protoctists and bacteria. Viruses are also pathogens even though they’re not living organisms
Cells can be eukaryotic or prokaryotic. eukaryotic cells are complex and include animal and plant cells. Prokaryotic cells are smaller and simpler like bacteria
Organelles are tiny structures within cells that you can only see through a microscope
Nucleus
an organelle that contains the genetic material that controls the cell’s activities. It is surrounded by its own membrane
Cell membrane
forms the outer surface of the cell and controls the substances that go in and out
Cytoplasm
a gel like substance where most of the cells chemical reactions happen. It contains enzymes which control these reactions
Mitochondria
small organelles where most of the reactions for anaerobic respiration take place. respiration transfers energy that the cell needs to work
Ribosomes
small organelles where proteins are made in the cell
Chloroplasts
where photosynthesis occurs. Chloroplasts contain a green substance called chlorophyll which is used in photosynthesis
Cell wall
a rigid structure made of cellulose which surrounds the cell membrane. it supports the cell and strengthens it
Vacuole
a large organelle that contains cell sap, it helps to support the cell
Plant cells
Usually have all the organelles
Chloroplasts
Where photosynthesis happens, which makes food for the plant. Contain chlorophyll used in photosynthesis.
Cell wall
A rigid structure made of cellulose, which surrounds the cell membrane. It supports and strengthens the cell.
Vacuole
A large organelle that contains cell sap (a weak solution of sugars and salts). It helps to support the cell.
Tissue
A group of similar cells that work together to carry out a particular function
Plant tissues
Xylem (for transporting water and mineral salts)
Phloem (for transporting sucrose and amino acids)
A tissue can contain more than one cell type
Organ
A group of different tissues that work together to perform a function
Organs
Lungs in mammals
Leaves on plants
Organ system
Organs working together to do a different job e.g the digestive system in mammals
Most cells are specialised to carry out a certain function so their structures can vary
e.g red blood cells for carrying oxygen and white blood cells for defending the body against disease
Cell differentiation is the process by which a cell changes to become specialised for its job, as cells change they develop different organelles and turn into different types of cells. this allows them to carry out specific functions