Cells Flashcards
What is the purpose of cytoplasm
It is where chemical reactions take place (catalysed by enzymes)
What is the purpose of the nucleus
It controls the activities of the cell and carries the genetic information as genes
What is the purpose of the Mitochondria
Release energy for the cell through aerobic respiration (use of sugars and oxygen)
What is the purpose of the Cell membrane
Controls what goes in and out of cells
What is the purpose of the Ribosomes
Carry out protein syntheses
What is the purpose of the cell wall
Made of cellulose. Provides extra protection and strength
What is the purpose of the vacuole
Contains cell sap for storage and to maintain the shape of the cell
What is the purpose of the Chloroplasts
Contain chlorophyll to carry out photosynthesis
How do you calculate magnification
Magnification= eyepiece lens mag x object lens mag
How do you work out the actual size of an object if you know it’s magnification
Actual size= image size (AIM)
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Magnification
How many micrometers in a millimetre
1000
How many nanometers in a micrometer
1000
What is the highest magnification of a light microscope
X1500
How do electron microscopes work?
It fires a beam of electrons at the object
How much can an electron microscope magnify?
X2 million
What is an organelle
A small structure within the cell (mitochondria, ribosomes etc)
What is classified as eukaryotes?
Plants, animals, fungi, protictista
What does something have to have to be a eukaryote?
All of their cells must contain a true neucleus
What is classified as prokaryotic
Bacteria
What is a cell that evolved before the existence of a nucleus called?
Prokaryote
What are the differences between a prokaryote and a eukaryote
They have no nucleus(instead a loose collection of dna called a bacterial chromosome
They may have extra loops of dna (plasmids)
Cell wall
Might have a slime capsule for protection
Flagella for movement
How do bacteria reproduce
Binary fission
How do you grow bacteria
- sterilise pipette in Bunsen flame
- open and take a few drops of the broth culture in the pipette
- innoculate the agar by placing the broth in the centre
- Spread the culture on the whole surface
(Place an antibiotic disk on the plate to see how they affect growth) - Seal the lid
When growing bacteria what temperature do you culture them at and why
20-25 degrees because you don’t want to grow pathogens that could be potentially harmful to a person (37 degrees)
How do small organisms absorb oxygen and nutrients
Diffusion
Name 4 specialised cells
Muscle cell Red blood cell Sperm cell Nerve cell Root hair cell Leaf (palisade cell) Fat cell Eye (cone) cell
