Topic 3 Flashcards
Two fundamental groups of cell?
Prokaryote and Eukaryote
Plants Cells extra Organelles?
- Vacuoles
- Chloroplasts for Photosynthesis
- Cell wall made of cellulose
Similarities of Eukaryotic and Prokaryotic Cells
- Contain organelles
- Cell surface membrane both made of Phospholipid Bilayer (responsible for passage of substances)
Differences of Eukaryotic and Prokaryotic Cells
Pro - make up single celled organisms (Bacteria)
Eu - complex organisms (Animals, Plants)
Eukaryotic Cells are larger and more complex
Differences between fungal cells and plant cells
- No Chloroplasts in fungal cells
- Cell wall made of Chitin not Cellulose
Nucleus Function
-Contains cells DNA, surrounded by Nuclear Envelope
Mitochondria Function
- Site for respiration
- Site for ATP production
Structure of Golgi Apparatus?
-Series of flattened membrane sacs
Function of the Golgi Apparatus?
- Transport Vesicles from ER and fuse with Golgi Apparatus
- Transport Vesicles empty proteins and lipids into lumen of Golgi Apparatus
- As Proteins and Lipids travel through Golgi, they are stored and packaged
Structure of Golgi Vesicles?
- Membrane bound, fluid filled vesicles in cytoplasm
- Eg Lysosomes
Function of Golgi Vesicles?
-Store and transport modified proteins and lipids from Golgi Apparatus to target cells
Functions of Lysosomes?
-Aid Breakdown of Proteins, lipids eg
Structure of Ribosomes?
- Free Floating in cytoplasm or attached to side of ER
- Made of protein sub-units, not covered by a membrane
Function of Ribosomes?
-Protein Synthesis
Structure of ER?
- Series of interconnected membranous sacs and tubules
- Membrane of ER is a phospholipid bilayer embedded with proteins
- SER has no ribosomes
- RER has many on surfaces
Function of RER?
-Processing and folding of proteins
Function of SER?
-Making and processing of lipids
Structure of Plasma Membrane?
- Fluid Mosaic Model
- Made up of components (Phospholipids,Proteins,Cholesterol)
Role of Phospholipids in Plasma membrane?
- primary component (contain hydrophobic/hydrophilic heads)
- Hydrophilic Outwards/Hydrophobic Inside
Function of Plasma Membrane?
- Protect cells from surrounding environment
- Semi-Permeable meaning some substances can pass through
Structure of Cell Walls?
- Rigid Covering which protect cells
- Plant, fungal, algal all have this
- Fungal - Chitin
- Plant/Agal - Cellulose
What is Cellulose?
Polysaccharide made up of Glucose Units
Features of Plasma Membrane?
- Involved in Cell signalling
- Fluid
- Semi-Permeable
Structure of Centrioles?
-Cylindrical Shape made up of parallel microtubules
Function of Centrioles?
-Help Organise mitotic spindle during Cell Division
Mitosis - Interphase
- Cell prepares to divide
- Two copies of Chromosome
- ATP produced - Cell division
Mitosis - Prophase
- Nuclear Envelope breaks down
- Chromosomes coil more tightly (light microscope)
- Centrioles move to opposite poles
Mitosis - Metaphase
- Chromosomes line up along mid-line of cell
- Condensed more
- Attached to a spindle by Centromere
Mitosis - Anaphase
- Chromosomes break into two chromatids
- Spindles push chromatids to opposite poles
Mitosis - Telephase
- Chromosomes reach opposite poles
- Begin to unravel
- Nuclear Envelopes form around chromosomes
- Cytoplasm Splits two envelopes
- Daughter cells formed
Mitosis steps Acrynym
- I
- Picked
- My
- Apples
- Today
Mitosis - Asexual Reproduction
- Produces identical cells - clonal organisms
- No shuffling of genes
- Only one parent cell
- No genetic variation
Step 1 - Cell Root Tip Core Practical
1) Sample Preparation
- Wear Gloves
- Sprouting root tips
- Placed in 5M hydrochloric Acid
Step 2 - Cell Root Tip Core Practical
2) Cut Root Tips
- Use sharp scalpel - 2mm long
- Place on microscopic slide
Step 3 - Cell Root Tip Core Practical
3) Staining
- 2-3 drops of stain, leave for 2 minutes
- Place Cover strip
Step 4 - Cell Root Tip Core Practical
4) Squashing
- Squash Down - applying force to cover strip
Step 5 - Cell Root Tip Core Practical
5) Viewing the Sample
- Place on Microscope - lowest power lens
- Power 400x - more powerful so should see chromosomes
Steps of Cell Root Tip Core Practical
1) Prepare Sample
2) Cut Root Tips
3) Stain Root Tips
4) Squash Root Tips
5) View Root Tips on 400x power microscope
Centriole
-Cylindrical organelles which are involved in development of Spindle Fibres
Cytokinesis
-Division of Cytoplasm, separates into two daughter cells
Chromatids
- Two thread like strands when chromosome divides
- Each contains double helix
Centromere
-central region of chromosome which microtubules attach to spindle
What is a Flagella used for?
-Used for Locomotion
What is the Pili used for?
-Exchange genetic material called conjugation
What is the Fimbriae used for?
-Used by Bacteria to attach a host cell
Bits in Prokaryotes
- Lacks Membrane Bound Organelles
- No Nucleus
- Plasmids (singular circular DNA)
- Polysaccharide capsule
What is the Cell Cycle?
-Cells on path to cell division
2 Phases of the Cell Cycle?
- Interphase
- Mitotic Phase
What is Interphase in the Cell Cycle responsible for?
-Cells grow and DNA replicated
3 Growth Stages - Interphase Cell Cycle?
- G1 - Cell Grows
- S - DNA synthesis occurs
- G2 - Grows more before mitotic stage
What is Mitotic phase in the Cell Cycle responsible for?
-Replicated DNA and cytoplasmic contents are separated
Meiosis Definition
-Produces haploid gamete cells from Diploid Cells
What are Gametes?
- Sex Cells
- Haploid
Genetic Variation in Meiosis?
- Produces 4 different daughter cells
- Different combinations of chromosomes
Two Ways Genetic Variation Occurs?
- Crossing Over
- Independent assortment
What is Crossing Over?
- Chromosomes of Homologous pair lined up down middle
- Sections of DNA swapped between chromosomes
What is Independent Assortment?
- Chromosomes in a homologous pair are separated in a random formation
- Produces 2 daughter cells
What is Epigenetic regulation
-interacts with DNA to control access of DNA
Chromatin Structure
- Combination of DNA and Histomes
- Surrounded by chemical layer called epigenome
Epigenome
- Interacts with chromatin to change structure
- Covers chromatin
Epigenome effect on Chromatin
- More condensed - prevents transcription factors from binding to DNA
- Less Condensed - transcription factors easier access
Function of Epigenetic markers on Chromatins
- Makes it more or less condensed when epigenetic markers are attached to histone
- Alter chromatin structure
Examples of Epigenetic Markers
- Methyl groups
- Acetyl groups
Effect of Increased Methylation
- Methyl binds to CpG (Cytosine/Guanine) site on DNA
- Caused Chromatin to be condensed
- transcription facotrs cannot reach DNA
- Inhibits Transcription
Effect of Decreased Methylation
- Removed from Histone proteins
- Increased positive charge on histones
- Increases attraction to phosphate groups on DNA
- Chromosome condenses
When Chromatin is condensed…
- Increased Methylation
- Decreased Acetylation
When Chromatin is less condensed…
- Decreased Methylation
- Increased Acetylation
