Term
Cell size
Eukaryotes
Bacteria
Viruses
Membrane |
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Definition
Eukaryotes = up to 100um
Bacteria = 1um
Viruses =100nm
Membrane = 10nm
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Term
| Surface area to volume ratio |
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Definition
Large organisms have a low ratio, they can't lose or gain heat quickly,they can't diffuse substances easily so they need lungs and body systems.
Small organisms have a high ratio, can lose and gain heat quickly and diffuse substances easily. |
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Term
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Definition
| Cells that have certain unused genes swithched off so that the cell does a specific job. |
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Term
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Definition
Cells that are undifferentiated, they still have all of their genes switched on. Found in early embryos.
Could be used for medicine and research Controversial- cells are from aborted embryos |
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Term
Prokaryotic cells
-Draw and label a diagram |
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Definition
Simplest cell structure
Bacteria and blue green algae.
Cell wall, plasma membrane, cytoplasm, nucleoid, ribosomes, pilli . |
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Term
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Definition
| Prevents bursting during osmosis in a dilute solution and maintains shape. |
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Definition
| Seperates the cell from the outside environment and controls what enters and exits the cell. |
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Definition
| Naked DNA , no nuclear membrane |
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Term
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Definition
Made of RNA and protein. The site of protein synthesis (amino acids, translation)
Slightly different structure to eukaryotes |
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Term
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Definition
Nucleus
Golgi apparatus
Mitochondria
Rough endoplasmic reticulum
Ribosomes
Lysosomes |
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Term
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Definition
| Contains DNA wrapped around histone proteins, has a nuclear membrane |
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Term
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Definition
A system of membranes
Used for packaging proteins into vesicles for use outside and inside thte cell. |
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Term
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Definition
Slightly different to prokaryotic ribosomes (80S)
Free- make proteins for use mainly inside the cell
E.R- make proteins for use in and outside the cell
Made of RNA and protein, the site of translation |
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Term
| Rough endoplasmic reticulum |
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Definition
Attatched to the nuclear envelope.
Some ribosomes attatched
makes proteins for use mainly outside the cell.
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Definition
| The site of aerobic respiration after the link reaction. |
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Definition
| Vesicles containing enzymes for digestion when the cell is fused with a food vacuole. |
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Term
Fluid mosaic model of a biological membrane-
Phospholipid bilayer |
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Definition
Phospholipid
Polar head- hydrophilic
Fatty acid tails- hydrophobic
Glycoproteins
Integral proteins
Inner and outer peripheral proteins
Cholesterol |
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Term
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Definition
When a substace cannot pass through a membrane (water, ions) becuase of it's charge etc it has to go through a channel protein to avoid the hydrophbic fatty acid tails.
This is a type of passive transport. |
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Term
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Definition
This does not require the breakdown of ATP for energy.
Particles move through channel protiens to an area of lower concentration
eg Diffusion
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Term
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Definition
| Requires the breakdown of ATP for energy so substances can be moved accross a membrane often against a concentration gradient, eg glucose. |
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Definition
The random movement of particles from an area of high concentration to lower concentration.
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Definition
| The random movement of water through a semi-permeable membrane from an area of low solute concentration to an area of high solute concentration. |
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Term
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Definition
A small amount of substance surrounded by a membrane eg lysosomes, food vacuoles.
The rough e.r packages protiens produced by ribosomes into vesicles which can then be sent to the golgi apparatus and then secreted.
The membrane seperates the substace and the cell to prevent damage, digestion etc. |
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Term
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Definition
When a vesicle joins with the cell membrane and the contents are secreted from the cell.
The cell membrane is like liquid so it can seperate and merge easily. |
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Definition
| Large molecules cannot cross cell membranes so a part of the membrane envelops the molecule and is it absorbed into the cell. |
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Term
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Definition
Cell replication of somatic cells
Interphase
Prophase
Metaphase
Anaphase
Telophase
Cytokinesis |
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Term
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Definition
There are 3 stages: G1 phase, S phase, G2 Phase
G1= Growth of cell after cytokinesis until the beginning of mitosis, the daughter cells are small
S phase= protein synthesis, DNA replication
G2 =The cell prepares for mitosis
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Term
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Definition
| The 46 chromosomes begin to supercoil and can be seen as X's. The nuclear envelop dissolves so the chromosomes are in the cytoplasm |
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Term
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Definition
| Spindle fibres begin to grow at each end of the cell. Chromosomes line up at the equator of the cell and the spindle fibres attach to the centromeres. |
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Term
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Definition
| The spindle fibres contract and pull the chromatids to opposite ends of the cell |
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Term
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Definition
| New nuclear membranes form creating two nuclei. The cell membrane pinches together |
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Term
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Definition
The cell splits into two daughter cells which are exact replicas of the parent cell.
The next stage is G1 interpahse becuase they are half the size of the original cell. |
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