MCB L1 Flashcards
Describe the structure of prokaryotes
Simple structure - no nucleus
DNA not localised, “free”, attached to cell wall, cell membrane (plasma membrane)
Outer cell wall - protection (prokaryotes live in hostile environments)
Variable shapes + sizes (rods, spheres, spirals)
State the 3 different shapes of prokaryotes
Spherical cells
Rod shaped cells
Spiral cells
State an example of a prokaryote
Bacteria:
Archae
Eubacteria - ecoli (model organism for eubacteria)
Diagram of prokaryote
Prokaryotic DNA
Ribosomes
Cell Membrane
Cell Wall
Flagellum
How do prokaryotes become resistant to antibioitics
Rapid growth due to frequent divisions
Leads to rapid evolving
-change in genetics (genetic replication)
-Exchange of DNA between cells
-Mutations
Leads to antibiotic resistance
State a common type of antibiotic resistanct prokaryote
MRSA - post surgery infection
people get infected with MRSA (antibiotic resistant bacteria, post surgery)
What are the components of the plasma membrane?
DNA
RNA
Proteins
State the 3 divisions of organisms
Bacteria (eubacteria)
Archae (Archaebacteria)
Eukaroytes
How do we classify the different divisions of organisms?
We cannot do this based on how they look, they all have similar shapes and sizes
We can only do this based on DNA sequence
What are the two divisions of prokaryotes?
Prokaryotes diverged early in evolution into 2 distinct groups:
Eubacteria
Archae
State 2 examples of eukaryotes
Humans
Maize
State an example of archaebacteria
Sulfolobus
State an example of eubacteria
E-coli
State the compartments of the eukaryotic cell
RECOGNISE ON DIAGRAM
- Plasma membrane
- Nucleus
- Ribosomes in cytosol
- Mitochondrion
- Lysosomes
- Golgi apparatus
- ER
- Vesicles
- Peroxisomes
- Centrosome with pair of centrioles
- ECM
- Actin Filaments
- Intermediate filaments
- Microtubules
State the function of the nucleus
Contains genome
DNA + RNA synthesis
State the function of lysosomes
Intracellular digestion / degradation
State the function of ER
Synthesis of proteins + lipids
(where cell membrane components are made, the above)
(materials for export)
State the function of golgi apparatus
Modifications, sorting, packaging of proteins + lipids (of materials produced in ER)
Transports materials outside cell using vesicles
State the function of endosomes
Sorting of molecules entering cell via membranes
State the function of mitochondria
ATP synthesis
Cellular respiration
State the function of peroxisomes
Oxidation of toxic molecules
State the function of chloroplasts
Traps sunlight energy - converts into large molecules
“large molecules” = food, used for ATP synthesis in mitochondira
Why do eukaryotyes have membrane-bound organelles
Organelles in eukaryotes are in membrane-bound compartments
Because each organelle undergoes seperate reactions which are NOT COMPATIBLE with each other - therefore, organelles need to be in seperate comparments
Describe the structure of the golgi apparatus
Flattened stacks of membrane enclosed sacs
State the function of the plasma membrane
Allow materials to be imported and exported from the cell via endocytosis and exocytosis
What is the cytoplasm ?
All aqeous material in plasma membrane
What is the cytosol ?
All cytoplasm not enclosed in membrane bound organelles
What is the role of the cytosol ?
- Many chemical reactions take place in cytosol
- e.g. initial breakdown of nutrients
What are diverse cell types ?
Specialised cells.
Certain cells are specialised for certain functions and therefore, have different quantities of certain components
Give examples of diverse cell types
- Oxyntic cells (stomach)
- Astrocytes (brain)
- Cardiac muscle cells (heart)
- Egg cells / Sperm cells (sex cells)
- Hair cells (inner ear)
State the function of oxyntic cells, where they are found and how they are specialised to this function
Found in stomach
Produce gastric juice which produces HCl
Have lots of mitochondria
