3.2 Cells Flashcards
3.2.1.1 Structure of eukaryotic cells
What organelles do eukaryotic cellls contain?
Hint: contains 10 organelles.
- CSM
- Nucleus
- Mitrochondira
- Chloroplasts (in plants and algae)
- Golgi apparatus and Golgi vesicles.
- Lysosomes
- Ribosomes
- Rough endoplasmic reticulum and smooth endoplasmic reticulum.
- Cell wall (in plants, algae and fungi)
- Cell vacuole. (in plants)
3.2.1.1 Structure of eukaryotic cells
Structure and function of CSM.
STRUCTURE
Found in all cells.
Phospholipid bilayer: molecules embedded within and attached on outside (proteins, carbohydrates, cholesterol.)
FUNCTION
controls what enters and exits the molecule.
3.2.1.1 Structure of eukaryotic cells
Structure and function of nucleus.
STRUCTURE
1. Nuclear envelope: double membrane surrounding the nucleus. Controls entry and exits of materials in and out of nucleus.
2. Nuclear pores: allows passage of large molecules out of nucelus i.e. mRNA.
3. Nucleoplasm: Granular jelly-like material.
4. Chromosome: protein-bound linear DNA.
5. Nuceolous: Smaller sphere inside which is a site of rRNA production and makes ribosomes.
FUNCTION
Site of DNA replication and transcription (making mRNA)
Contains genetic code for each cell.
Manufactures rRNA and ribosomes.
3.2.1.1 Structure of eukaryotic cells
Structure and function of mitrochondria.
STRUCTURE
Double membrane.
Inner membrane called cristae.
Fluid centre called mitrochondrial matrix.
Loop of mitrochondira DNA.
FUNCTION
Site of aerobic respiration.
Site of ATP production.
DNA to code for enzymes needed in respiration.
3.2.1.1 Structure of eukaryotic cells
Structure and function of chloroplast.
STRUCTURE
1. Chloroplast envelope: double plasma membrane. Controls entry and exit of substane within chloroplast.
2. Grana: stacks of 100 disc-like called thylakoid } contains chlorophyll. 1st stage of photosythesis (light absorption)
3. Stroma: fluid-filled matrix. 2nd stage of photosynthesis. contains starch grains.
FUNCTION
1. Site of photosynthesis.
2. Granal membrane: provide large surface area for attachement of chlorophyll, electron carriers and enzymes in first stage of photosynthesis.
3. Fluid of stroma: posseses enzymes needed to make sugars in 2nd stage of photosynthesis.
3.2.1.1 Structure of eukaryotic cells
Structure and function of golgi apparatus and golgi vesicle.
STRUCTURE
1. Folded membranes making cisternae.
2. Secretary vesicles pinch off from the cisternae.
3. More curved in apperance but may look like SER.
FUNCTION
1. Add carbs to proteins to form glycoprotein.
2. Produce secretory enzymes.
3. Secrete carbs
4. Transport, modify and store lipids.
5. Form lysosomes.
6. Molecules “labelled” with their destination.
7. Finished products are transported to cell surface in golgi vesicles where they fuse with membrane and contents in released.
3.2.1.1 Structure of eukaryotic cells
Structure and function of lysosomes.
STRUCTURE
1. Bags of digestive enzymes.
2. Membrane bound organelle that releases hydrolytic enzymes.
FUNCTION
1. Hydrolyse phagocytic cells.
2. Completely break down dead cells
3. Exocytosis - release enzymes to outside of cell to destory material.
4. Digest worn out organelles for reuse of materials.
3.2.1.1 Structure of eukaryotic cells
Structure and function of ribosomes.
STRUCTURE
1. Small, made up of two sub-units of protein and rRNA.
2. **80s ** large ribosome found it eukaryotic cells
3. 70s smallers ribosome found in prokaryotic cells, mitochondria and chloroplasts.
FUNCTION
site of protein synthesis.
3.2.1.1 Structure of eukaryotic cells
Structure and function of RER.
STRUCTURE
Series of flattened sacs enclosed by a membrane with ribosomes on surface.
FUNCTION
1. Provides large SA for synthesis of proteins / glycoproteins.
2. provides pathway for transport of materials through cells especially proteins.
3.2.1.1 Structure of eukaryotic cells
Structure and function of SER.
STRUCTURE
1. system of membrane bound sacs.
2. doesn’t contain ribosomes on its surface
FUNCTION
1. sythesis, store and transport lipids and carbs.
3.2.1.1 Structure of eukaryotic cells
Structure and function of cell wall.
(inside plant cells not animal)
STRUCTURE
1. Consist of number of polysaccharides i.e. cellulose embedded in matrix.
2. Thin layer } middle lamellae.
FUNCTION
1. Provides mechanical strength in order to prevent cell from bursting under osmotic pressure by the entry of water.
2. provides strength to plant as a whole.
3. allows water to pass along it.
3.2.1.1 Structure of eukaryotic cells
Structure and function of cell wall in algae.
STRUCTURE
made up of cellulose or glycoproteins or both.
FUNCTION
same as plant cell wall function.
3.2.1.1 Structure of eukaryotic cells
Structure and function of cell wall in fungi.
STRUCTURE
do not contain cellulose, instead contain chitin, glycan (polysaccharide) and glycoproteins.
FUNCTION
3.2.1.1 Structure of eukaryotic cells
Structure and function of cell vacuole.
STRUCTURE
1. fluid filled sac bound by a single membrane.
2. Plant vacuoles may contain: solution of mineral salt, sugars, amino acids, wastes and pigments.
FUNCTION
1. Supports herbaceous plants by making cells turgid.
2. Sugars and amino acids may act as temporary food stores.
3. Pigment can colour petals, attracting pollinating insects.
3.2.1.1 Structure of eukaryotic cells
How are specialised cells organised into?
C lark
T ripped
O ver
O llies
O bjects
Cells, tissues, organs, organ system, organisms.
3.2.1.2 Structure of prokaryotic cells and of viruses
How do prokaryotic cells differ from eukaryotic cells?
- Cytoplasm lacks membrane bound organelles.
- Smaller ribosomes (70s).
- No nucleus ; single circular DNA molecule free in cytoplasm not associated with proteins / histones
- Cell wall contains murein, a glycoprotein.
- No chloroplast
- Contains capsule surrounding the cell.
- +1 plasmids
- +1 flagella
3.2.1.2 Structure of prokaryotic cells and of viruses
Function of capsule.
protects bacterium from other cells and helps groups of bacteria to stick together for further protection.
3.2.1.2 Structure of prokaryotic cells and of viruses
Function of circular DNA.
Posseses genetic info. for replication of bacterial cells.
3.2.1.2 Structure of prokaryotic cells and of viruses
Function of plasmids.
Posseses genes that may aid survival of bacteira in harmful conditions i.e. producing enzymes that can break down antibiotics.
3.2.1.2 Structure of prokaryotic cells and of viruses
Structure and function of a virus.
STRUCTURE
1. acellular and non-living particles.
2. Smaller than bacteria
3. Contain nucleic acids } DNA or RNA but can only multiply inside living host cells.
4. Capsid: nucleic enclosed within protein.
5. Attachment proteins: Lipid envelope or capsid have AP, allow virus to identify and attach to a host cell.
HIV further surrounded by lipid envelope.
3.2.1.3 Methods of studying cells
Define magnification.
how many times bigger the image produced by the microscope is than the real-life object you are viewing
3.2.1.3 Methods of studying cells
Define resolution.
ability to distinguish between objects that are close together.
(i.e. the ability to see two structures that are very close together as two separate structures)
3.2.1.3 Methods of studying cells
What are the two main types of microscopes?
- Optical microscope (Light)
- Electron microscope.
3.2.1.3 Methods of studying cells
Describe an optical (light) microscope.
Use light to form an image.
Light microscopes use a pair of convex glass lenses that can resolve images that are 0.2um apart.