Cell structure + Movement of molecules Flashcards
What are the levels of organisation?
- Organelles
- Cells
- Tissues
- Organs + Organ systems
What is the function of a NUCLEUS?
Membrane - bound organelle containing genetic material.
What is the function of CYTOPLASM?
Material that fills the cell to facilitate chemical reactions and hold organelles in place.
What is the function of a CELL MEMBRANE?
Phospholipid bilayer that controls movement of substances into and out of the cell.
What is the function of a CELL WALL?
External to cell membrane that protects + mantains the shape of cell.
What is the function of MITOCHONDRIA?
Carry out cellular respiration
What is the function of CHLOROPLASTS?
Carry out photosynthesis.
What is the function of RIBOSOMES?
Site of protein synthesis.
What is the function of a VACUOLE?
Storage organelle in plants to store water + dissolved substances.
Similarities + differences between animal and plant cells
Similarities: cell membrane, nucleus, cytoplasm, ribosomes, mitochondria
Differences: cell wall, vacuole, chloroplasts
What is the definition of diffusion?
- It is the net movement of particles moving from a high concentration to a low concentration.
- Random movement of particles meaning its a passive process and requires no energy.
What is a concentration gradient?
Difference of concentration between two areas
What is osmosis?
- Movement of water particles from a high concentration of water molecules to a low concentration of water molecules through A PERMEABLE MEMBRANE.
What is active transport?
-Movement of molecules from a low concentration to a high concentration (AGAINST THE CONCENTRATION GRADIENT).
Through a carrier protein using energy from respiration.
For what is active transport used?
Used to continue transport of small amounts of remaining nutrients against concentration gradient.
Where does active transport take place?
Small intestine (uptake of glucose)
Root hair cells (uptake of ions from soil water)
Plant (uptake of ions from soil water)
For what is energy required in active transport?
To change the shape of the carrier protein.
Describe process of active transport
- Low concentration outside cell + high concentration inside cell.
- Carrier protein uses energy from respiration to change its shape, moving substance into cell.
- Substance moved into cell against concentration gradient + carrier molecule uses energy supplied from repiration to drive movement across cell membrane.
- Molecule is then released into cell.
How is the energy in active transport sometimes called?
ATP - (energy created by respiration)
What are the factors that affect the rate of movement of substances into and out of cells?
DISTANCE TRAVELLED - greater distance = slower rate of diffusion.
CONCENTRATION GRADIENT - greater difference in concentration = faster the diffusion.
MASS OF MOLECULES - heavier the molecules = move slower, slower rate of diffusion (+ viceversa)
TEMPERATURE - higher temperature = increases energy therefore movement of molecule increases at rate of diffusion.
