Biology AQA 3.1.3 Cells

Description

Unit 1 Biology, Aqa specification 3.1.3
evie.daines
Flashcards by evie.daines, updated more than 1 year ago
evie.daines
Created by evie.daines almost 10 years ago
3583
119

Resource summary

Question Answer
Structure of an epithelial cell from the small intestine.
PLASMA MEMBRANE: Appearance: found on the surface of animals cells and inside the wall of plant cells and prokaryotic cells. It is made up of proteins and lipids. Function: regulates movement of substances in and out of cells. it also has receptors which responds to hormones and chemicals.
MICROVILLI: Appearance: These are folds in the plasma membrane Function: Involved in processes like absorption and they increase the surface area of the plasma membrane
NUCLEUS: appearance: A large organelle surrounded by a nuclear envelope( double membrane) It contains many pores and the nucleus contains chromatin and often a nucleolus Function: Chormatin is made from proteins and this makes up DNA which controls the cells activities. The pores allow substances to move in and out and the nucleus makes ribosomes.
LYSOSOME: Appearance: A round organelle surrounded by a membrane with no clear internal structure. Function: Contains digestive enzymes and are used during phagocytosis and they digest invading cells or break down worn components of the cell.
RIBOSOME: Appearance: A small organelle that floats free or is attached to a rough endoplasmic reticulum. Function: This is the site where proteins are made.
ENDOPLASMIC RETICULUM: Appearance: SMOOTH: system of membranes enclosing a fluid filled space ROUGH:Is similar to smooth but is covered in ribosomes. Function: SEM synthesises and processes lipids. REM folds and processes proteins that have been made by ribosomes.
GOLGI APPARATUS; Appearance: A group of fluid filled flattened sacs. Function: Processes and packages new lips and proteins. It also makes lysosomes.
MITOCHONDRION: Appearance: They have a double membrane and the inner membrane is folded to form cristae, inside this is the matrix which contains enzymes involved in respiration. Function: The site of aerobic respiration. Found in large numbers are active and require lots of energy.
Prokaryote: Before nucleus Eukaryote: After Nucleus
Transmission Electron Microscopes Electrons are fired onto the specimen which then absorbs electrons. this then causes an image to be produced on a screen *The whole thing must be in a vacuum *A complex staining process *Image is black and white * Specimen must be thing *Image might contain artefacts Scanning Electron Microscopes Same limitations as a transmission. However the specimen doesnt need to be thin as a 3D image can be produced.
Magnification: Magnification= Size of image/ size of object M= I/o (MILO) Resolution: The minimum distanceof two objects for them to appear seperate
Cell Fractionation: the process where cells are broken up in a c cold, isotonic and buffered solution. Cold: Reduce enzyme activity Isotonic: To prevent organelles bursting or shrinking Buffered: to maintain a constant PH
Ultracentrifugation: Process by which fragments are seperated. 1. The tube is spun at a slow speed. 2. The heaviest organelles (the nucleus) are forced to the bottom of the tubes, they then form a sediment. 3. The fluid at the top is removed leaving the nucleus 4. the fluid is then spun again and the heaviest sinks and the organelles continue to be seperated
Show full summary Hide full summary

Similar

GCSE AQA Biology - Unit 2
James Jolliffe
Cells - Biology AQA B2.1.1
benadyl10
Cells, Tissues and Organs
yusanr98
Biology Unit 1a - GCSE - AQA
RosettaStoneDecoded
GCSE AQA Biology 1 Quiz
Lilac Potato
Biology AQA 3.2.5 Mitosis
evie.daines
B1.1.1 Diet and Exercise Flash Cards
Tom.Snow
GCSE Biology AQA
isabellabeaumont
AQA Biology 8.1 structure of DNA
Charlotte Hewson
B3 Quiz
Tess Brockway
AQA Biology 12.1 cellular organisation
Charlotte Hewson