Eukaryotic cells Flashcards
(27 cards)
What are the two types of microscope
Light microscope
Electron microscope
How do you calculate total magnification
Magnification of objective lens X magnification of eyepiece lens
Advantages and disadvantages of light microscope
Advantages - can see living things directly, relatively cheap so more widely available, light and portable
Disadvantages - preservation and staining tissue can produce artefacts in the tissues so what we see may be the result of preparation, also has limited powers of resolution and magnification
Resolution
A measure of how close together two objects can be before they are seen as one
What is the current model for the cell membrane
Fluid mosaic model
What is endosymbiotic theory
A theory that suggests that mitochondria and chloroplasts originated as independent prokaryotic organisms
What makes up the phospholipid bilayer
Phospholipid
Gylcolipid
Glycoprotein
Protein (integral / channel)
Cholesterol
Function of the phospholipid bilayer
Creates a barrier between internal and external contents of the cell
Location for chemical reactions
Cellular respiration signalling
Easy for hydrophobic molecules to pass through (hydrophilic molecules are polar and dime it difficult to pass through)
What is the purpose of cholesterol in the cell membrane
Controls fluidity of the membrane
More cholesterol = more rigid / less fluidity
Cytoskeleton
3D web structure
Microfilaments contract for movement
Consists of microfilaments and microtubules
Keeps organelles in place
Nucleus
Has a nucleolus
Largest organelle
Nuclear envelope controls movement of chemicals
Production of ribosomes
Mitochondria definitions and 5 key points
Cristae- the folds
Matrix - fluid filled
Has a double membrane
Fluid matrix surrounds cristae
Produced ATP
Inner membrane is folded
Mitochondria provide energy
80S vs 70S ribosomes
80S - found in eukaryotic cells, made up of 60s and 40s subunits
70S - usually found in prokaryotic cells, made up of 50s and 30s subunits
Both - synthesise proteins, consist of large and small subunits, made up of ribosomal RNA and proteins
Cell theory and the 3 principles
States cells are a fundamental unit of structure, function and organisation in all living organisms
3 principles:
1. All organisms are made up of cells
2. All existing cells are produced by other living cells
3. The cell is the most basic unit of life
Robert Hooke
The first person to look at and name cells
He looked at non living cork cells
They reminded him of small rooms in monasteries called cells
Cell organisation
Organelle
Cell
Tissue
Organ
Organ system
Organism
Protein transport
Protein leaves nucleus through nuclear pore
Enters rough ER which has 80s ribosomes
Folds and balls up proteins
Packages protein into vesicle
Enters Golgi which modifies vesicles
Either released in a Golgi vesicle (leaves through exocytosis) or a lysosome to target old cells or pathogens
What do plant cells have that animal cells don’t
Chloroplasts
Cell wall
Vacuole
Chloroplast
Make their own food
Contain their own DNA
Double membrane
Chlorophyll makes it green (photosynthesis) to absorb more light
Formed by a leucoplast
Cell wall
Contains mitochondria which produce ATP
Gives plants strength and support - prevents osmotic lysis
Made of cellulose (insoluble)
Consists of several layers
Vacuole
Occupies 80% of the cell
Contains sap (pigments, enzymes, waste)
Specialised membrane (tonoplast)
Keeps cell rigid / turgid
What are the 4 key tissues
Nervous tissue
Epithelial tissue
Connective tissue
Muscular tissue
Simple squamous cells
Very thin
Used in alveoli (one cell thick) making it easy for oxygen to pass through
Cuboidal + columnar cells
Thicker
Line other tubes in the body (provide structure)
