B1 - Cells And Organisation Flashcards
How many metres in a kilometre?
1000m
How many centimetres in a metre?
100cm
How many millimetres in 1cm?
10mm
How many micrometers in a millimetre?
1000 μm
How many nanometers in a micrometer?
1000nm
What are the features of a microscope?
Objective lens, Eyepiece lens, stage, clip, coarse focus, fine focus, slide, diaphragm lever, condenser, noise piece, mirror/light and stage height adjustment
How do you calculate magnification?
Eyepiece lens strength (e.g x4) x objective lens adjustment (e.g x100)
How to calculate the real size of an object?
Image size ÷ magnification
How to calculate magnification?
Image size ÷ size of real object
How to work out image size?
Magnification x size of real object
What features are in an animal cell?
Nucleus, Cell membrane, cytoplasm, mitochondria, ribosomes, Golgi apparatus, cytoskeleton, rough and smooth endoplasmic reticulum
What features are there in a plant cell?
Nucleus, Cell membrane, cytoplasm, mitochondria, ribosomes, Golgi apparatus, permanent vacuole, cell wall, chloroplasts.
What is a nucleus?
The nucleus controls all the activities of the cell and is surrounded by the nuclear membrane. It contains genes on the chromosomes that carry the instructions for making proteins needed to build new cells and organisms.
What is cytoplasm?
Cytoplasm is a liquid gel in which the organelles are suspended and where most of the chemical reactions needed for life take place
What is the cell membrane?
The cell membrane controls the passage of substances such as glucose and mineral ions into the cell. It also controls the movement of substances such as urea or hormones out of the cell
What are the mitochondria?
The mitochondria are structures in the cytoplasm where aerobic respiration takes place, releasing energy from the cell.
What are ribosomes?
The ribosomes are where protein synthesis takes place, making all the proteins needed in the cell
What is the cell wall?
A cell wall is a wall made of cellulose that strengthens and gives the cell support
What are chloroplasts?
Chloroplasts contain the green substance chlorophyll. Chlorophyll absorbs light so the plant can make food by photosynthesis. Root cells do not have chloroplasts because they are underground
What is a permanent vacuole?
A permanent vacuole is a space in the cytoplasm filled with cell sap. This is important for keeping the cells rigid to support the plant
What is a Golgi apparatus?
The job of the Golgi apparatus is to process and bundle macromolecules like protein or lipids as they are synthesised inside the cell. Golgi apparatus is sometimes compared to a post office inside the cell since one major function is to modify, sort, and package proteins to be secreted.
What is a rough ER?
This is an organelle that is based on producing proteins. It is called rough because it has ribosomes on it. It synthesises protein cells and stores them until they are moved to the Golgi apparatus for packaging.
What is the smooth ER?
The smooth ER is similar to the rough ER but it is about the storage and creation of lipids and hormones. It stores and distributes these products around the cell.
What are algae?
Algae are simple aquatic organisms that make there own food via photosynthesis. It has similar features to plant cells. It used to be classed as a plant cell but is classed as Protista now.
What is a eukaryotic cell?
This is a cell which contains cytoplasm, cell membrane and that genetic material that is stored in the nucleus.
What is a prokaryotic cell?
- unicellular organism
- no nucleus
- no membrane bound organelles
- most have cell walls
What is the definition of diffusion?
diffusion is the net movement of particles from an area of high concentration to low concentration
What 3 factors affect rate of diffusion?
- temperature = more energy means the particles move faster
- diffusion distance = shorter distance is quicker
- concentration gradient = the bigger the difference between low concentration and high concentration, the faster it will diffuse
Give 3 examples of substances that travel into cells via diffusion?
Oxygen in
Carbon dioxide out
Glucose in
Give an example in the body for an adaptation for better diffusion
Villi = large surface area and thin cells make a smaller diffusion distances creating faster diffusion
Is diffusion passive or active?
Passive. It requires no energy
Is active transport active or passive?
Active. It requires energy
Describe active transport
Plant transport proteins recognise ions or sugars
They use energy from respiration to bring them inside the cell
They move from low concentration to high concentration
The protein reverts back to normal waiting for another molecule
Is osmosis passive or active?
Passive. It requires no energy
Describe osmosis
Water goes from high concentration to low concentration of water molecules through semi permeable membranes
What does isotonic mean?
Where the amount of solute (eg salt) is equal in the cell and outside the cell
What is hypotonic?
Hypotonic is where the concentration of solutes outside the cell is lower than inside the cell
What is hypertonic?
Hypertonic is where the concentration of the solute is higher outside the cell than inside
What is turgor pressure?
It is the pressure applied to the cell wall when water gets into plants
