B1 Cell structure and transport Flashcards
What is a eukaryotic cell
Cells with genetic material enclosed in a nucleus
What is a prokaryotic cell
dont have a nucleus to enclose genetic material
Contains DNA in loops
Has one larger loop of DNA and a smaller one called am plasmid
What is the cell membrane
The border of all types of cells
Controls the movement of substances in and out of the cell
What is the nucleus
Contains all genetic information
Controls the activities of the cell
What happens in the cytoplasm
Most chemical reactions
What happens in the mitochondria
Aerobic respiration
What is made in the ribosomes
Proteins (protein synthesis)
What are chloroplast
Subcellular structures responsible for photosynthesis
Plant cells only
What is the permanent vacuole
A subcellular structure filled with cell sap (store of nutrients for the cell)
Plant cells only
What is the cell wall
Made from cellulose
Strengthens the cell
Plant cells only
What is DNA
Holds genetic information in the cell
What is a plasmid
Small loop of DNA
Only found in prokaryotic cells
Allow bacteria to swap gen
etic information
What is a specialised cell
A cell with a specific job of or function
What is differentiation
The way cells become specialised
Develop new features to help them perform a specific function
What is a tissue
A group of cells with similar structures or functions
A tissue is formed when these cells begin to work together
What is an organ
Collection of tissues performing a specific function
What is an organ system
Several organs working together
What is a light microscope
You can see large subcellular structures like the nucleus but not much else
What is the magnification
How much the microscope can enlarge the object
What is the resolution
The measure of the level of detail you can see with a microscope
What is an electron microscope
Has a much higher magnification and resolution than electron microscope
Essential for discovering the smaller subcellular structures
What is diffusion
The net movement of particles from a high concentration to a low concentration
Happens across cell membranes
Does not require energy
What is the concentration gradient
The difference in concentration of a substance between 2 places
A steeper concentration gradient means there is a bigger difference in concentration
What processes in the body work through diffusion
Oxygen transported into the blood stream
Carbon dioxide is transported out
How urea moves from cells into the bloodstream
What affects the rate of diffusion
Steepness of concentration gradient
Temperature (Higher temp= Higher rate of diffusion)
Surface area of membrane
Diffusion pathway
Distance over which a substance must diffuse
What is osmosis
The diffusion of water from a dilute to a concentrated solution across a partially permeable mebrane
What is active transport
The movement of substances against the concentration gradient. Requires energy from respiration
Give an example where active transport happens in plants
Root hair cells absorb mineral ions from the very dilute solution in the soil
Give an example where active transport happens in animals
Absorption of sugar from the intestine into the blood
What does an exchange surface need to effectively exchange substances with the environment
Large surface area
Thin wall/membrane for a short diffusion pathway
Where does gas exchange happen in most animals
Alveoli in the lungs
What is the function of the stomata
Control gas exchange in leaves by opening and closing and are involved in loss of water from leaves
What are the 4 key parts of the gas exchange system
Trachea
Bronchus
Bronchiole
Alveoli
What happens in the alveoli
Oxygen moves into the blood and carbon dioxide moves out
Adaptations of alveoli to maximise gas exchange
Large surface area
Thin walls-Short diffusion distance
