B2.1 Cells and Simple Cell Transport Flashcards
What do animal cells contain? (5)
Nucleus, cytoplasm, cell membrane, mitochondria and ribosomes
What purpose does the nucleus have in an animal cell?
It contains the genetic material that controls the activity of the cell
What purpose does the cytoplasm have in an animal cell?
Cytoplasm is a gel-like substance where most of the chemical reactions take place - it contains enzymes that control these chemical reactions
What purpose does the cell membrane have in an animal cell?
It holds the cell together and controls what goes in and out
What do plants cells contain? (8)
Mitochondria, cell wall, nucleus, a permanent vacuole, cell membrane, ribosomes. chloroplasts and cytoplasm
What purpose does the cell wall have in a plant cells?
The cell wall is a rigid structure made of cellulose, it supports and strengthens the cell
What purpose does the permanent vacuole have in a plant cells?
It contains cell sap - a weak solution of sugar and salts
What purpose do chloroplasts have in a plant cells?
This is where photosynthesis occurs, which makes the food for the plant - they contain a green substance called chlorophyll which absorbs the light energy for photosynthesis
What are yeast cells and bacterial cells an examples of?
A single-celled organisms
What does a yeast cell contain? (4)
Cytoplasm, a cell membrane, a cell wall and a nucleus containing genetic material
What do bacterial cells contain?
A cell membrane, a cell wall, cytoplasm and genetic material
Why do bacterial cells contain genetic material floating in it’s cytoplasm?
Because they don’t have a nucleus
What is a specialised cell?
A cell which performs a specific function
What helps a specialised cell with its job?
The cell’s structure e.g. its shape and parts it contains
What are examples of specialised cells? (4)
Sperm cells, egg cells, and red blood cells (animals) and palisade leaf cells (plants)
What are sperm and egg cells specialised for?
Reproduction
What is the main function of an egg cell?
To carry the female DNA and to nourish the developing embryo in the early stages
What does an egg cell contain so it can carry out its function?
Huge food reserves to feed the embryo
What is the main function of sperm cells?
To get the male DNA to the female DNA
How is a sperm adapted to carry out its function?
It has a long tail and a streamlined head to help it swim to the egg, and it also contains lots of mitochondria to provide the cell with the energy it needs to swim to the egg
What is the main function(s) of a red blood cell?
To remove waste products from cells and to give oxygen to cells
How does a red blood cell’s shape help it to carry out its function?
They have a biconcave shape (both sides of the cell curve inwards) which gives them a large surface area for absorbing oxygen, this shape also helps to pass through blood capillaries to reach blood cells
What does a red blood cell contain (or not contain) to help it with its function?
Red blood cells are packed with haemoglobin - the pigment that absorbs oxygen and they don’t have a nucleus so there is even more room for haemoglobin
What is the main function of a palisade leaf cell?
Photosynthesis
Where are palisade cells found? How does this help them with there function?
They are group at the top of a leaf as this is where the sun hits the leaf
How does a palisade cell’s shape help it with its function?
They are tall with long sides which means they have more surface area exposed for absorbing carbon dioxide from the air in the leaf - they are also thin so you can pack loads at the top of a leaf
What do palisade leaves contain a lot of? And why?
They are packed with chloroplasts which absorbs the light energy for photosynthesis
Where are the majority of chloroplasts found In a palisade leaf cell?
They are crammed near the top of the cell so they’re nearer to the light
What is diffusion?
The spreading out of particles from an area of high concentration to an area of low concentration
Where does diffusion occur?
In solutions and gases - because the particles are free to move around about randomly
What can move in and out of cells?
Dissolved substances
What can pass through cell membranes?
Small molecules like oxygen, glucose and amino acids - big molecules like protein and starch cannot
What is it called when there are a lot more particles on one side of a membrane than the other?
There’s a net movement from that side
What increases the rate of diffusion?
The larger the difference in concentration, the faster the diffusion rate
