Biology Paper 1 Flashcards
What does Solute mean?
Something which dissolves
E.g Sugar
What does Solvent mean?
The liquid which dissolves the solute
What does Soluble mean?
When a substance will dissolve
What does Insoluble mean?
When a substance cannot be dissolved
What does Concentrated mean?
A solution with many solute particles
What does dilute mean?
A solution with few solute particles
What is a solution?
The resulting mixture of solute and solvent
What is Osmosis?
Osmosis is the movement of water molecules .
High concentration to Low concentration
Where does water always move in Osmosis?
Water always moves to where the most solute is
What does isotonic mean?
Both sides of the cell membrane are at equilibrium
What does hypertonic mean?
A high solute
What does hypotonic mean?
A low solute
Why does water move to the high concentration of solute molecules?
It is where the most water is present
What would happen if a freshwater fish was placed in a salt water tank?
It would shrivel up and die as the water is moving towards the highest amount of solute which is outside the tank. The tank is hypertonic while the fish is hypotonic.
Sweets placed in a hypotonic solution will….
swell/ grow as the solution has less solute than the sweet
Sweets placed in a hypertonic solution will….
shrink as the solution has more solute than the sweet
Sweets placed in an isotonic solution will…
Be stable as the solution is at equilibrium
What is the equation for rate of osmosis?
Change in Mass (g) / Time (min) = Rate of osmosis
What is an enzyme?
A biological catalyst that increase the speed of a chemical reaction
Protein that breaks large molecules into small molecules, helping fast digestion
What are the reactions of photosynthesis and how they can be absorbed?
- Carbon dioxide (absorbs through leaves)
- Water (absorbs through roots and transports to leaves)
Also need light and chlorophyll in the leaves
What is the balanced symbol equation for photosynthesis?
6CO2 + 6H2O light + chlorophyll C6H12O6 + 6O2
What is the word equation for photosynthesis?
Carbon Dioxide + Water —–> Glucose + Oxygen
What type of reaction is photosynthesis?
An endothermic reaction. It requires energy in the form of light
What is the function of a root hair cell?
To absorb water and minerals from the soil
How are root hair cells adapted?
They are 1 cell thick
They have a large surface area
What does the adaptation help?
Absorbing water quicker
What is active transport?
The carrying of dissolved molecules across a cell membrane from a lower to a higher concentration by moving up or against a concentration gradient.
Does Active Transport require energy?
Yes it gets it from mitochondria
Does Osmosis require energy?
No
Does Diffusion require energy?
No
Does Active transport require a membrane?
Yes it is semi-permeable
It requires a carrier protein
Does Osmosis require a membrane?
Yes it is a permeable membrane
Does Diffusion require a membrane?
No
What is a membrane?
The cell membrane controls the movement of substances in and out of the cell
What is an example of Active Transport and what does it transport?
Root hair cells
Minerals
What is an example of Osmosis and what does it transport?
Root hair cell
Water
What is an example of Diffusion and what does it transport?
Carbon dioxide through stomata for photosynthesis
What is a stomata?
Tiny holes found in the underside of the leaves
What is the concentration gradient in Active Transport?
Goes against the concentration gradient
Low to High
What is the concentration gradient in Osmosis?
Down a concentration gradient
High to Low
What is the concentration gradient in Diffusion?
Down a concentration gradient
High to Low
How would you make a rainbow rose?
Put the stem in the water
What does Transpiration mean?
Movement of Water
Evaporation of water from a plants surface area
What does Translocation mean?
Movement of Sugar
What is the function of the xylem?
Transports water and dissolved minerals from roots to the leaves
What is the function of the Phloem?
Transports sugars around the plant
What is the cell structure of a Xylem?
- Thick cell walls
- Hollow
- Dead Cells
- Cell wall made of cellulose
What is the cell structure of a Phloem?
- Small holes at the end of cells
- Made of living cells
Are Xylem cells continuous tubes?
No
Are Phloem cells continuous tubes?
Yes
What is the direction of flow in a Xylem?
Upwards
(roots to leaves)
What is the direction of flow in a Phloem?
Both directions
What is the process which substances in a Xylem are moved?
Osmosis
Transpiration