Day 25 (biology) Flashcards
What is the movement of water from a higher to lower concentration of water across a partially permeable membrane?
Osmosis
What do we call the types of transport that don’t require any energy?
Passive
What is the difference in the number of particles in two areas called?
Concentration gradient
What factor speeds up diffusion by giving particles less far to travel?
Decreased distance
What factor speeds up diffusion by increasing the number of particles available to move?
Increased concentration gradient
What factor speeds up diffusion by giving particles more energy, making them move faster?
Increased temperature
What factor speeds up diffusion by increasing the area available for particles to move into?
Increased surface area
Why do red blood cells burst in a solution of pure water?
Water moves in by osmosis and they have no cell wall
What happens to plant cells in a solution of pure water?
They are turgid- the cell membrane pushes against the cell wall
What happens to plant cells in a solution of salty water?
They are plasmolysed- the cell membrane shrinks away from the cell wall
Why should a pregnant lady or athlete consume more energy rich foods than someone who works in an office?
Higher energy requirement- more is used
What is the wave of muscle contraction that pushes food through the gut called?
Peristalsis
What is it called when bile breaks large fat droplets into smaller ones?
Emulsification
Why does bile need to be alkaline?
Neutralisation of stomach acid
Why does bile need to do emulsification and neutralisation?
To give optimum pH and large surface area for enzymes
