Osmosis, Diffusion, Active Transport Flashcards
Why can’t plant cells burst
Because they have cell walls
What is the concentration gradient of Osmosis
High water potential to Low water potential
What is osmosis
The overall movement of water molecules from a high to low water potential across a semi permeable membrane
What are the small dots
Water molecules
What are the bigger dots
Sugar molecules
What is the word to describe an plant cell which pressure has increased
Turgor pressure to then turgid
What do plants do when there cells have become flaccid ( due to a lack of turgor pressure )
They wilt
What happens when there is a decrease in turgor pressure in a plant cell
It becomes plasmalysed
Why does a plant cell become turgid and why does a plant cell become flaccid or plasmalysed
It becomes turgid Because the plant cell has a LOWER water potential than the solution it is in and vis Verda for when it becomes flaccid or plasmalysed
What happens when the solution has the same water potential as the the plant cell
The cell remains the same
When the water potential in the solution is higher than a red blood cell what happens to it
It swells and may burst. This is called lysis
What happens when then water potential in the solution is lower than the cell
It crinkles up/ it becomes crenated
What is active transport
Is the net movement of molecules against the concentration gradient. A protein carrier in the membrane carries the molecules across
What does active transport allow cells to do
It allows cell to move substances from an area of low concentration to an area of high concentration
What does active transport require
ATP ( energy )
When concentration gradient does active transport move in
Low to high concentration
How does it work
- ) a potassium particle attaches to the carrier protein
- ) the carrier protein uses energy to change shape
- ) the potassium particle moves inside the the cell
Fact
Active transport pumps particles against a concentration gradient
What part of the cell produces ATP
Mitochondria
What are 2 plant cells
Pallaside cells and Root hair cells
What helps replace, repair, grow, asexual reproduction
Mitosis
What must happen before a cell divides
DNA must replicate
How do they divide
Mitosis
What type of organism Differentiates
Multicellular organisms
What is the function of pallaside cells
Photosynthesis
How have palisade cells been specialised
- ) near surface of leaf
- ) packed full of chloroplast
- ) keeps regular shape
How have root hair cells been specialised
Larger surface area so that they can get more nutrients from the soil
What happens when a cell is specialised
It’s structure changes so that it is better adapted to perform its function
What is an alternative option instead of using embryonic stem cells
Adult stem cells from bone marrow
What can Embryonic stem cells do
They can change into anything whereas adult stem cells can only change into few different types of cell
Where are stem cells found in plants
Meristem cells which have a thinner wall so they can divide. These are found in ; shoots or flowers, root tip.
Why do meristems divide
To make the stem thicker
Why can’t differentiated plant cells divide
Thick cell wall
Cell division steps
- ) 2 strands separate
- ) this exposes the bases ( A,C,G,T)
- ) free nucleotides line up using the base pairing rules
- ) the nucleotides are joined into 2 new strands of DNA
What is mitosis
A form of cell division
Mitosis steps
- ) DNA is replicated
- ) Chromosomes line up at the centre of the cell
- ) the replicated double chromosomes ( still one though ) split.
- ) the nucleus reforms around each set of chromosomes
- ) then you have 2 new genetically identical “daughter” cells
What is the definition of diffusion
The net movement of anything generally from a region of higher concentration to a region of lower concentration
