Biology 2.1
Resolution: Ability to distinguish between 2 different points in a specimen.
• Optical – Determine by wavelength of light (large wavelength)
• Electron – Determined by wavelength of beam of electrons (much smaller that light). Specimen must also be in
vacuum
Magnification: How much bigger an image appears compared to the original object (calculated using the following formula:
Use Fluorescent
Preparing slide
• Dry mount, thin slices or whole specimen on slide, covered
with cover slip.
• Wet mount, water added to specimen before cover slip with
mounted needle to prevent air bubble.
Aquatic organisms should be viewed this way.
• Squash slide, wet mount which is them pushed down on cover
slip – e.g. help view chromosomes in mitosis.
• Smear slide, use edge on another slide and smear sample
across slide, creates smooth thin even coated specimen. Place
cover slip on to – used to examine blood.
Graticule
Stains in Microscopes - 1) Line up micrometer and eyepiece graticule, looking through the eyepiece
Methylene Blue = all-purpose stain 2) Count number of division of eyepiece graticule per 1 division in the
Differential Staining: micrometer.(e.g. 2 eyepiece graticule = 1 micrometer)
Acetic orcein = DNA, chromosomes (dark red) 3) 1 division in micrometer = 10 micro meters
Eosin = Cytoplasm E.g. 10 micro meter divide by 2 = 5 micro meter, which is one eyepiece
Sudan = Lipids (red) graticule length.
Iodine = Cellulose (yellow), Starch (blue/black)
mm x1000= micro meters
Structure Function
Nucleus Nuclear envelope – double membrane - Nuclear envelope – separates content of nucleus
Nuclear Pores - from rest of the cell
Nucleoplasm – granular, jelly like - Site of DNA replication and transcription
Chromosomes - protein bound, linear DNA - Contains the Genetic Code for each cell
Nucleolus -Site of RNA production and make - Nucleolus - Site of Ribosome synthesis
ribosomes.
RER Fluid Filled Cavities – Cisternae Intracellular transport system
Coated with ribosomes Provides large SA for ribosomes, to allow more efficient
protein synthesis.
SER Fluid Filled Cavities – Cisternae Contains Enzymes that catalyse reactions involved in
No ribosomes lipid metabolism.
Synthesis – cholesterol, lipids/phospholipids, steroid
hormones.
Involved in absorption, synthesis and transport of
lipids.
Golgi Apparatus + Vesicles Folded membranes made of cisternae Process, modify proteins.
Secretary vesicles pinch off from cisternae Add sugar = glycoprotein
Add lipid = lipoprotein
fold into 3D shape
Package into vesicle + pinched off to be store in cells
of moves to plasma membrane.
Ribosomes Made of 2 subunit protein and rRNA Site of protein synthesis
80s – large ribosomes in eukaryotic cells
70s – smaller ribosomes found in prokaryotic cells
Mitochondria Double Membrane Site of aerobic respiration
Inner membrane called cristae Site of ATP production
Fluid Centre = Mitochondrial Matric DNA, codes for enzyme needed for respiration
Loop of mitochondria DNA
, Lysosome Bag of digestive enzyme – can contain 50 different Hydrolyse phagocytic cells
enzyme Autolysis - complete break-down in dead cells
Can be created by Golgi Exocytosis – release enzymes to outside of cell to
destroy material
Digest worn out organelles for reuse of materials
Chloroplast Double membrane Site of photosynthesis
Contains Thylakoids
Fluid filled stroma – contain enzyme for
photosynthesis, found in plants
Plasma Membrane Found in all cells Controls the entrance and exit of molecules
Phospholipid bilayer – molecules embedded withing
and attached outside (e.g. protein, carbohydrates,
cholesterol)
Centrioles Made of microtubules Involve in production of spindle fibre and organisation
Occur in pairs making a centrosome of chromosomes in cell division
Cell Wall Found in Plant and Fungi – Eukaryotic cells only Provides structural strength to the cell
Plants – Made of microfibrils of the cellulose polymer
Fungi – Made of Chitin, a nitrogen-containing
polysaccharide
Flagella Whip like structure For mobility and sometimes as a sensory organelle for
chemical stimuli
Cilia Hairlike projections out of cells Can be mobile or stationary
Mobile cilia – helps move substances in a sweeping
motion (in airways)
Stationary cilia – important in sensory organs like in the
nose.
Vacuole Surrounded by a membrane called the tonoplast and Large permanent vacuole, filled with water and
contains fluid solutes, maintains cell stability
Importance of cytoskeleton:
Structure –
• Network of fibre found within the cytoplasm all over a cell.
• Consists of microfilaments, microtubules and intermediate fibres
• Cytoskeletal motor proteins (myosin, kinesins and dyneins) are molecular motors,
Function –
• Provides mechanical strength, helps maintain the shape and stability of a cell. – Many organelles are bound to the
cytoskeleton.
• Microfilaments are responsible for cell movement
• Microtubules are responsible for cell to change shape during endocytosis, exocytosis , phagocytosis, etc.
• Intermediate fibres provide mechanical strength
Key differences between prokaryotic and eukaryotic cells: Similarities Between prokaryotic and eukaryotic cells:
• Prokaryotic Cell are much smaller • They both have plasma membrane
• No membrane bound organelles • Cytoplasm
• Smaller ribosomes • Ribosomes
• DNA is not in a nucleus • DNA and RNA
• Cell wall made of peptidoglycan
,Biology 2.2
Water –
Polar Molecule, unevenly distributed charge.
Hydrogen Bonds form between O s- and H s+ of separate water molecules, weak bond.
Properties:
Liquid, provide habitat, major component in tissues on living organisms, reaction medium, effective transport medium.
Density, ice is less dense than water – acts are insulator in ponds when cold, organisms can have stable environment in winter.
Solvent, good solvent – mineral and ions can react and move around/transported, (cytoplasm).
Cohesion and Surface tension, water in flat surface doesn’t spread (spherical due to H bonds, cohesion), H bond cause water
molecule to be more attracted to each other than air above allowing water to be able to resist force applied to it.
- columns of water can be formed in plant vascular tissue, pond-skaters can walk on water.
High Specific Heat Capacity, lots on energy is needed to increase their kinetic energy and temperature.
- stable environment for enzyme controlled reactions and for aquatic organisms.
High latent heat of vaporisation, H bonds cause large amount energy for water molecules to evaporate.
Reactant, e.g. photosynthesis, digestion. Allows synthesis of large biological molecules.
Monomer: An individual unit that can be bonded to other identical monomers to make a polymer.
Polymers: Molecules made from a large number of monomers joined together.
Biological Molecules:
Hydrolysis reaction: Breaking a chemical bond between two molecules involving the
use of a water molecule C, H and O for carbohydrates
Condensation reaction: A type of reaction that joins two molecules together with the C, H and O for lipids
formation of a chemical bond involving the elimination of water. C, H, O, N, S for proteins
C, H, O, N, P for nucleic acids
Carbohydrates: Have Glycosidic Bonds
Monosaccharide – simplest carbohydrates. (carbohydrate)
The glycosidic bond to form disaccharide and polysaccharides.
Disaccharide: (glycosidic bond)
44
, Type of polysaccharide Structure
Good energy store – compact, in
chains, less soluble in water
Starch - Plant Amylose Coil into spiral shape, H bonds Straight Helix
Long a-glucose molecule holds the spiral.
Has glycosidic bonds – between
carbon 1 and 4.
Amylopectin Coil into spiral shape, H bonds Branched . 1,4 + 1,6
This is amylose with glycosidic bonds holds the spiral.
between C 1,4 and C 1,6. Branches also emerges from
the spiral.
Glycogen - Animals Glycogen Less tendency to coil, more More Branched 1,4 + 1,6
Like amylopectin with smaller 1,4 branched, so more compact
bonded carbon chains and still have and easier to remove.
1,6 carbon chain.
Cellulose 1,4 glycosidic – helps prevent chain spiralling.
H bond in chain also give extra strength and stop spiralling
Alternate B-glucose is inverted Cellulose chains in Plant Cell wall:
- 1,4 glycosidic bonds 60 – 70 cellulose chain = Microfibril (embedded in pectin)
400 Microfibril = Macrofibril
- Straight chain
Structure and function of plant cell walls:
- High tensile strength, due to H bond and glycosidic bonds.
Other Structural Polysaccharides: - Criss crossing the wall for extra strength
- Bacterial Cell Wall, peptidoglycan - Difficult to digest cellulose, most animals don’t have enzyme to catalyse the reaction
Key feature of plant cell wall that helps to do it job:
- Exoskeleton, chitin - don’t have rigid skeleton to support whole plant
- cell wall is fully permeable
- high tensile strength
- lignin makes plant waterproof
Lipids: Have Ester Bonds - triglyceride, phospholipids and steroids.
Triglyceride –A type of lipid formed from a molecule of glycerol joined by ester bonds to three
fatty acid molecules. Lipids:
Macromolecule
Non polar molecule
Insoluble in water
Dissolve in organic solvent, like ethanol
Hydrophobic
Fatty acid
Resolution: Ability to distinguish between 2 different points in a specimen.
• Optical – Determine by wavelength of light (large wavelength)
• Electron – Determined by wavelength of beam of electrons (much smaller that light). Specimen must also be in
vacuum
Magnification: How much bigger an image appears compared to the original object (calculated using the following formula:
Use Fluorescent
Preparing slide
• Dry mount, thin slices or whole specimen on slide, covered
with cover slip.
• Wet mount, water added to specimen before cover slip with
mounted needle to prevent air bubble.
Aquatic organisms should be viewed this way.
• Squash slide, wet mount which is them pushed down on cover
slip – e.g. help view chromosomes in mitosis.
• Smear slide, use edge on another slide and smear sample
across slide, creates smooth thin even coated specimen. Place
cover slip on to – used to examine blood.
Graticule
Stains in Microscopes - 1) Line up micrometer and eyepiece graticule, looking through the eyepiece
Methylene Blue = all-purpose stain 2) Count number of division of eyepiece graticule per 1 division in the
Differential Staining: micrometer.(e.g. 2 eyepiece graticule = 1 micrometer)
Acetic orcein = DNA, chromosomes (dark red) 3) 1 division in micrometer = 10 micro meters
Eosin = Cytoplasm E.g. 10 micro meter divide by 2 = 5 micro meter, which is one eyepiece
Sudan = Lipids (red) graticule length.
Iodine = Cellulose (yellow), Starch (blue/black)
mm x1000= micro meters
Structure Function
Nucleus Nuclear envelope – double membrane - Nuclear envelope – separates content of nucleus
Nuclear Pores - from rest of the cell
Nucleoplasm – granular, jelly like - Site of DNA replication and transcription
Chromosomes - protein bound, linear DNA - Contains the Genetic Code for each cell
Nucleolus -Site of RNA production and make - Nucleolus - Site of Ribosome synthesis
ribosomes.
RER Fluid Filled Cavities – Cisternae Intracellular transport system
Coated with ribosomes Provides large SA for ribosomes, to allow more efficient
protein synthesis.
SER Fluid Filled Cavities – Cisternae Contains Enzymes that catalyse reactions involved in
No ribosomes lipid metabolism.
Synthesis – cholesterol, lipids/phospholipids, steroid
hormones.
Involved in absorption, synthesis and transport of
lipids.
Golgi Apparatus + Vesicles Folded membranes made of cisternae Process, modify proteins.
Secretary vesicles pinch off from cisternae Add sugar = glycoprotein
Add lipid = lipoprotein
fold into 3D shape
Package into vesicle + pinched off to be store in cells
of moves to plasma membrane.
Ribosomes Made of 2 subunit protein and rRNA Site of protein synthesis
80s – large ribosomes in eukaryotic cells
70s – smaller ribosomes found in prokaryotic cells
Mitochondria Double Membrane Site of aerobic respiration
Inner membrane called cristae Site of ATP production
Fluid Centre = Mitochondrial Matric DNA, codes for enzyme needed for respiration
Loop of mitochondria DNA
, Lysosome Bag of digestive enzyme – can contain 50 different Hydrolyse phagocytic cells
enzyme Autolysis - complete break-down in dead cells
Can be created by Golgi Exocytosis – release enzymes to outside of cell to
destroy material
Digest worn out organelles for reuse of materials
Chloroplast Double membrane Site of photosynthesis
Contains Thylakoids
Fluid filled stroma – contain enzyme for
photosynthesis, found in plants
Plasma Membrane Found in all cells Controls the entrance and exit of molecules
Phospholipid bilayer – molecules embedded withing
and attached outside (e.g. protein, carbohydrates,
cholesterol)
Centrioles Made of microtubules Involve in production of spindle fibre and organisation
Occur in pairs making a centrosome of chromosomes in cell division
Cell Wall Found in Plant and Fungi – Eukaryotic cells only Provides structural strength to the cell
Plants – Made of microfibrils of the cellulose polymer
Fungi – Made of Chitin, a nitrogen-containing
polysaccharide
Flagella Whip like structure For mobility and sometimes as a sensory organelle for
chemical stimuli
Cilia Hairlike projections out of cells Can be mobile or stationary
Mobile cilia – helps move substances in a sweeping
motion (in airways)
Stationary cilia – important in sensory organs like in the
nose.
Vacuole Surrounded by a membrane called the tonoplast and Large permanent vacuole, filled with water and
contains fluid solutes, maintains cell stability
Importance of cytoskeleton:
Structure –
• Network of fibre found within the cytoplasm all over a cell.
• Consists of microfilaments, microtubules and intermediate fibres
• Cytoskeletal motor proteins (myosin, kinesins and dyneins) are molecular motors,
Function –
• Provides mechanical strength, helps maintain the shape and stability of a cell. – Many organelles are bound to the
cytoskeleton.
• Microfilaments are responsible for cell movement
• Microtubules are responsible for cell to change shape during endocytosis, exocytosis , phagocytosis, etc.
• Intermediate fibres provide mechanical strength
Key differences between prokaryotic and eukaryotic cells: Similarities Between prokaryotic and eukaryotic cells:
• Prokaryotic Cell are much smaller • They both have plasma membrane
• No membrane bound organelles • Cytoplasm
• Smaller ribosomes • Ribosomes
• DNA is not in a nucleus • DNA and RNA
• Cell wall made of peptidoglycan
,Biology 2.2
Water –
Polar Molecule, unevenly distributed charge.
Hydrogen Bonds form between O s- and H s+ of separate water molecules, weak bond.
Properties:
Liquid, provide habitat, major component in tissues on living organisms, reaction medium, effective transport medium.
Density, ice is less dense than water – acts are insulator in ponds when cold, organisms can have stable environment in winter.
Solvent, good solvent – mineral and ions can react and move around/transported, (cytoplasm).
Cohesion and Surface tension, water in flat surface doesn’t spread (spherical due to H bonds, cohesion), H bond cause water
molecule to be more attracted to each other than air above allowing water to be able to resist force applied to it.
- columns of water can be formed in plant vascular tissue, pond-skaters can walk on water.
High Specific Heat Capacity, lots on energy is needed to increase their kinetic energy and temperature.
- stable environment for enzyme controlled reactions and for aquatic organisms.
High latent heat of vaporisation, H bonds cause large amount energy for water molecules to evaporate.
Reactant, e.g. photosynthesis, digestion. Allows synthesis of large biological molecules.
Monomer: An individual unit that can be bonded to other identical monomers to make a polymer.
Polymers: Molecules made from a large number of monomers joined together.
Biological Molecules:
Hydrolysis reaction: Breaking a chemical bond between two molecules involving the
use of a water molecule C, H and O for carbohydrates
Condensation reaction: A type of reaction that joins two molecules together with the C, H and O for lipids
formation of a chemical bond involving the elimination of water. C, H, O, N, S for proteins
C, H, O, N, P for nucleic acids
Carbohydrates: Have Glycosidic Bonds
Monosaccharide – simplest carbohydrates. (carbohydrate)
The glycosidic bond to form disaccharide and polysaccharides.
Disaccharide: (glycosidic bond)
44
, Type of polysaccharide Structure
Good energy store – compact, in
chains, less soluble in water
Starch - Plant Amylose Coil into spiral shape, H bonds Straight Helix
Long a-glucose molecule holds the spiral.
Has glycosidic bonds – between
carbon 1 and 4.
Amylopectin Coil into spiral shape, H bonds Branched . 1,4 + 1,6
This is amylose with glycosidic bonds holds the spiral.
between C 1,4 and C 1,6. Branches also emerges from
the spiral.
Glycogen - Animals Glycogen Less tendency to coil, more More Branched 1,4 + 1,6
Like amylopectin with smaller 1,4 branched, so more compact
bonded carbon chains and still have and easier to remove.
1,6 carbon chain.
Cellulose 1,4 glycosidic – helps prevent chain spiralling.
H bond in chain also give extra strength and stop spiralling
Alternate B-glucose is inverted Cellulose chains in Plant Cell wall:
- 1,4 glycosidic bonds 60 – 70 cellulose chain = Microfibril (embedded in pectin)
400 Microfibril = Macrofibril
- Straight chain
Structure and function of plant cell walls:
- High tensile strength, due to H bond and glycosidic bonds.
Other Structural Polysaccharides: - Criss crossing the wall for extra strength
- Bacterial Cell Wall, peptidoglycan - Difficult to digest cellulose, most animals don’t have enzyme to catalyse the reaction
Key feature of plant cell wall that helps to do it job:
- Exoskeleton, chitin - don’t have rigid skeleton to support whole plant
- cell wall is fully permeable
- high tensile strength
- lignin makes plant waterproof
Lipids: Have Ester Bonds - triglyceride, phospholipids and steroids.
Triglyceride –A type of lipid formed from a molecule of glycerol joined by ester bonds to three
fatty acid molecules. Lipids:
Macromolecule
Non polar molecule
Insoluble in water
Dissolve in organic solvent, like ethanol
Hydrophobic
Fatty acid
