Cell Structure and Replication (SR) Flashcards
What do Eukaryotes include?
Animal, Plant and Fungal Cells
What is the function of the Cell Surface Membrane? (A1/A8)
1) Controls entry of substance into the cell
2) Site of cell communication via receptors
What is the function of the cell Nucleus? (A2/A8)
1) Stores DNA
2) Nuclear Pores allow mRNA & ribosomes to pass through
What is the function of Mitochondria? (A3/A8)
Carry out Aerobic Respiration to produce ATP
What is the function of Lysosomes in cells? (A4/A8)
Contains digestive enzymes
To break down pathogens, old organelles, cells and food
What is the function of Ribosomes in cells? (A5/A8)
Site of Protein Synthesis
What is the function of the Rough Endoplasmic Reticulum (Rough ER)? (A6/A8)
Provide a large surface area
For Protein Synthesis
What is the function of the Smooth Endoplasmic Reticulum (Smooth ER)? (A7/A8)
Synthesise, store and transport lipids and carbohydrates
What is the function of the Golgi Apparatus? (A8/A8)
1) Modifies proteins
2) Sort, package, and transport molecules around the cell
What is the function of Chloroplasts? Where are they found? (O1/O3)
1) Site of Photosynthesis
2) Plants and Algae
What is the function of the Cell Vacuole? Where are they found? (O2/O3)
1) Maintains Cell Structure
Act as temporary energy store
2) Plants only
What is the function of the Cell Wall? Where is it found? (O3/O3)
1) Provides support & Mechanical Strength
2) Plants, Algae and Fungi
What happens to Eukaryotic cells in Complex Multicellular organisms?
Eukaryotic Cells become specialised for specific functions
What happens to specialised cells?
Organised into tissues
Tissues into Organs
Organs into Systems
What is the difference between Eukaryotic and Prokaryotic Cells?
Prokaryotes are smaller and simpler than Eukaryotes
1) Eukaryotes have a Nucleus, Prokaryotes don’t
2) Eukarotic DNA is linear and packaged into chromosomes in nucleus, Prokaryotic is circular and freely floating in cytoplasm
3) Both have Cell Membranes
4) Eukaryotes have Membrane-bound organelles, Prokaryotes don’t
5) Both have Ribosomes present (Euk 80S, Prok 70S)
6) All Prokaryotes have Cell Walls, some Eukaryotes have cell walls
7) Prokaryotes don’t have Chloroplasts, some Euks do
8) Euks don’t have plasmids, Proks do sometimes
9) Euks don’t have capsules, Proks do sometimes
10) One euk has a flagellum (sperm cell), Proks do sometimes
What are Eukaryotic Cell Walls made of (if it has one)?
Cellulose or Chitin
What are Prokaryotic Cell Walls made of?
Peptidoglycan
How do Bacteria replicate?
Binary Fission:
1) Cell replicates its DNA
2) Cytoplasmic membrane elongates, separating DNA molecules
3) Cross wall forms; membrane invaqinates
4) Cross wall forms completely
5) Two daughter cells are formed
What are Viruses?
Acellular and Non-living
What does the basic structure of Viruses consist of?
Capsid Genetic Material (Viral RNA, vRNA) Enzyme/s Matrix Lipid Envelope Attachment Protein
How do Viruses Replicate?
1) Bind to Host Cell
2) Inject Genetic Material into cell
3) Use Host’s machinery to replicate
4) Burst out of the host cell
What are the 3 types of microscopes used to observe cells?
1) Light Microscope
2) Scanning Electron Microscope (SEM)
3) Transmission Electron Microscope (TEM)
What are the properties of Light Microscopes? (M1/M3)
1) Light Beam Medium
2) Only in 2D
3) Max Magnification x1,500 (bigger the better)
4) Max Resolution 200nm (smaller the better)
What are the properties of Scanning Electron Microscopes (SEM)? (M2/M3)
1) Electron Beam Medium
2) 3D
3) Max Magnification x200,000 (bigger the better)
4) Max Resolution 20nm (smaller the better)
What are the properties of Transmission Electron Microscopes (TEM)? (M3/M3)
1) Electron Beam Medium
2) Only in 2D
3) Max Magnification x2,000,000
4) Max Resolution 0.1nm
What is Magnification?
How much bigger the image is
Compared to original object viewed with naked eye
What is the equation for Magnification?
Magnification = (Size of Image) / (Size of Object)
What is the Resolution?
How well a microscope distinguishes b/w 2 points that are close together
How can Cell Fractionisation be used to separate organelles?
1) Homogenisation - Grinding cells to release organelles into solution
2) Filtration - Separating Organelles and Debris
3) Ultracentrifugation - Using centrifuge, organelles separated in order of mass
What is Mitosis?
Nuclear Division of cells
What is Cytokinesis?
When cell splits in two
Forming two identical daughter cells
What are the 4 main phases of Mitosis? (CD1/CD5)
1) Prophase
2) Metaphase
3) Anaphase
4) Telophase
What occurs during Prophase? (CD2/CD5)
DNA Condenses and coils
Nuclear envelope breaks down
Centrioles move to opposite poles
What occurs during Metaphase? (CD3/CD5)
Spindle Fibres attach to Centromeres
Chromosomes line up at the Equator
What occurs during Anaphase? (CD4/CD5)
Centromeres divides
Chromatids move to opposite poles
What occurs during Telophase? (CD5/CD5)
Chromosomes uncoil
Nuclear Envelope reforms
What is wrong with Mitosis in Cancer Cells? What do treatments involve?
1) Cancerous cells have uncontrolled cell division
Hence have Modified Cell Cycle (repeats too quickly)
2) Treatments involve disrupting cell cycle (Chemotherapy, e.g. Cisplatin)
By stopping DNA Synthesis or by changing Cytoskeleton in Mitosis
