Week 1:
All cells have evolved from an ancestral cell of 3 billion years ago.
Prokaryotic:
- Resemble most closely the ancestral cell
- Very small, simple internal structure
- No membrane-bound organelles
- No membrane-bound nucleus
Bacteria, Archaea
Many bacteria have a flagellum, that rotates as a propeller to move the cell
forward.
Eukaryotic:
- Complex internal structure
- Membrane-bound organelles, present in the cytosol
- Membrane-bound nucleus
Protista, fungi, Plants, animals (plants + animal cells: 5-20 micrometers)
Evolution acquisition of mitochondria by engulfment of aerobic bacteria
Evolution acquisition of chloroplasts by engulfment of photosynthetic bacteria
Characteristic Prokaryotic Eukaryotic
Organelles No internal membrane- Internal membrane-bound
bound organelles. organelles.
Ribosomes Present Present
ER Absent Present
Cell wall Present, but the cell wall Present in fungi and plant
does not contain cellulose. cells.
Microtubules Absent Present
Nucleus Absent Present
Size Between 0.5 and 100 Between 10 and 150
micrometers micrometers
DNA Circular DNA Linear DNA
Plasma membrane Present Present
Electron microscope Light microscope
More resolution Less resolution
More magnification Less magnification
More expensive Less expensive
Shorter wavelength Longer wavelength
Heavy metals for contrast Dynamic processes visualized
Cells in vacuum Cells in liquid (alive!)
Fluorescence microscope: is used for
observing specific large molecules.
,They can be located in fixed or living cells. Fluorescent dyes absorb light at one wavelength
and emit it at another, longer wavelength. Is similar to the light microscope.
Resolution ( = resolving power): the ability to distinguish 2 points as separate dots, instead
of a single fuzzy dot.
D = the resolution
L = the wavelength
n = the refractive index of the medium between objective lens and coverslip
a = half-angle of the cone of light that can enter or exit the lens.
NA = the numerical aperture, this is written on the lens of the microscope
Viruses: they become active after they have entered the cell.
Transmission: the movement of light from one spot to another.
Golgi Apparatus: it modifies and sorts molecules that are made in the ER. It processes and
bundles the molecules for export and insertion in cell membranes.
Mitochondrion: it oxidizes food molecules to produce ATP. It contains its own circular DNA
and ribosomes. They contain a double membrane.
Chloroplasts: perform photosynthesis. They contain a double membrane.
Endosomes: they contain molecules that arrive in endocytosis vesicles. Early endosomes
develop into later endosomes. Molecules that need to be broken down are transported from
later endosomes to lysosomes.
Lysosomes: spherical vesicles that contain hydrolytic enzymes that can break down many
types of biomolecules.
Peroxisomes: they play a key role in the oxidation of specific biomolecules. Neutralization of
toxins.
Ribosomes: they serve as the site of biological protein synthesis.
Endoplasmic reticulum: plays a major role in protein synthesis, protein modification and fat
synthesis.
Cyanobacteria: they obtain energy through photosynthesis. They belong to the domain of
prokaryotes. Ozon (O3) is produced, which absorbs a lot of the sun’s UV-radiation.
Scientists use model organisms, such as E. coli or humans themselves.
Sugars:
, - Monosaccharides and polysaccharides
- Glucose: C6H12O6
- The hydroxyl groups (OH) of 2 monosaccharides can bind to a disaccharide via a
condensation reaction
- They can also bind with proteins and fatty acids.
Lipids:
- Hydrophobic hydrocarbon tail:
- Hydrophilic, polar carboxyl head: (-COOH)
- Saturated: single carbon bonds
- Unsaturated: a few double carbon bonds
- Lipids consist of 1 glycerol molecule and 3 fatty acids
- Multiple fatty acids form a lipid bilayer
- Phospholipids consist of glycerol + 2 fatty acids + phosphate + an additional polar
molecule
- Water is polar, so the polar, hydrophilic head is attracted to the water
Proteins:
- Proteins are built of amino acids. Amino acids contain an amino group (-NH 2) and
carboxyl group (-COOH)
- The amino acids are coupled by a peptide bond, via a condensation reaction
- The ribosomes make the peptide bonds
- The amino acids are categorized: nonpolar, polar-uncharged, polar-negatively +
polar-positively charged.
- Multiple linked amino acids are called polymers
Enzymes are proteins that can sometimes function as a biocatalyst: they lower the activation
energy, which increases the reaction rate. The shape of the catalytic center of enzymes
determine which substrates can bind to it induced fit.
The enzyme activity is dependent on the pH and temperature of the environment.
Week 2:
DNA
- DNA is a polymer, that is built up out of building blocks, nucleotides
- A nucleotide consists of 3 units: sugar, phosphate, base
- A nucleoside consists of a sugar and a base
Sugar = deoxyribose
Base = A, T, C & G (Adenosine, Thymine, Cytosine & Guanine)
All cells have evolved from an ancestral cell of 3 billion years ago.
Prokaryotic:
- Resemble most closely the ancestral cell
- Very small, simple internal structure
- No membrane-bound organelles
- No membrane-bound nucleus
Bacteria, Archaea
Many bacteria have a flagellum, that rotates as a propeller to move the cell
forward.
Eukaryotic:
- Complex internal structure
- Membrane-bound organelles, present in the cytosol
- Membrane-bound nucleus
Protista, fungi, Plants, animals (plants + animal cells: 5-20 micrometers)
Evolution acquisition of mitochondria by engulfment of aerobic bacteria
Evolution acquisition of chloroplasts by engulfment of photosynthetic bacteria
Characteristic Prokaryotic Eukaryotic
Organelles No internal membrane- Internal membrane-bound
bound organelles. organelles.
Ribosomes Present Present
ER Absent Present
Cell wall Present, but the cell wall Present in fungi and plant
does not contain cellulose. cells.
Microtubules Absent Present
Nucleus Absent Present
Size Between 0.5 and 100 Between 10 and 150
micrometers micrometers
DNA Circular DNA Linear DNA
Plasma membrane Present Present
Electron microscope Light microscope
More resolution Less resolution
More magnification Less magnification
More expensive Less expensive
Shorter wavelength Longer wavelength
Heavy metals for contrast Dynamic processes visualized
Cells in vacuum Cells in liquid (alive!)
Fluorescence microscope: is used for
observing specific large molecules.
,They can be located in fixed or living cells. Fluorescent dyes absorb light at one wavelength
and emit it at another, longer wavelength. Is similar to the light microscope.
Resolution ( = resolving power): the ability to distinguish 2 points as separate dots, instead
of a single fuzzy dot.
D = the resolution
L = the wavelength
n = the refractive index of the medium between objective lens and coverslip
a = half-angle of the cone of light that can enter or exit the lens.
NA = the numerical aperture, this is written on the lens of the microscope
Viruses: they become active after they have entered the cell.
Transmission: the movement of light from one spot to another.
Golgi Apparatus: it modifies and sorts molecules that are made in the ER. It processes and
bundles the molecules for export and insertion in cell membranes.
Mitochondrion: it oxidizes food molecules to produce ATP. It contains its own circular DNA
and ribosomes. They contain a double membrane.
Chloroplasts: perform photosynthesis. They contain a double membrane.
Endosomes: they contain molecules that arrive in endocytosis vesicles. Early endosomes
develop into later endosomes. Molecules that need to be broken down are transported from
later endosomes to lysosomes.
Lysosomes: spherical vesicles that contain hydrolytic enzymes that can break down many
types of biomolecules.
Peroxisomes: they play a key role in the oxidation of specific biomolecules. Neutralization of
toxins.
Ribosomes: they serve as the site of biological protein synthesis.
Endoplasmic reticulum: plays a major role in protein synthesis, protein modification and fat
synthesis.
Cyanobacteria: they obtain energy through photosynthesis. They belong to the domain of
prokaryotes. Ozon (O3) is produced, which absorbs a lot of the sun’s UV-radiation.
Scientists use model organisms, such as E. coli or humans themselves.
Sugars:
, - Monosaccharides and polysaccharides
- Glucose: C6H12O6
- The hydroxyl groups (OH) of 2 monosaccharides can bind to a disaccharide via a
condensation reaction
- They can also bind with proteins and fatty acids.
Lipids:
- Hydrophobic hydrocarbon tail:
- Hydrophilic, polar carboxyl head: (-COOH)
- Saturated: single carbon bonds
- Unsaturated: a few double carbon bonds
- Lipids consist of 1 glycerol molecule and 3 fatty acids
- Multiple fatty acids form a lipid bilayer
- Phospholipids consist of glycerol + 2 fatty acids + phosphate + an additional polar
molecule
- Water is polar, so the polar, hydrophilic head is attracted to the water
Proteins:
- Proteins are built of amino acids. Amino acids contain an amino group (-NH 2) and
carboxyl group (-COOH)
- The amino acids are coupled by a peptide bond, via a condensation reaction
- The ribosomes make the peptide bonds
- The amino acids are categorized: nonpolar, polar-uncharged, polar-negatively +
polar-positively charged.
- Multiple linked amino acids are called polymers
Enzymes are proteins that can sometimes function as a biocatalyst: they lower the activation
energy, which increases the reaction rate. The shape of the catalytic center of enzymes
determine which substrates can bind to it induced fit.
The enzyme activity is dependent on the pH and temperature of the environment.
Week 2:
DNA
- DNA is a polymer, that is built up out of building blocks, nucleotides
- A nucleotide consists of 3 units: sugar, phosphate, base
- A nucleoside consists of a sugar and a base
Sugar = deoxyribose
Base = A, T, C & G (Adenosine, Thymine, Cytosine & Guanine)
