Module 1 Flashcards
Characteristics of lipids
insoluble in water
dissolve in organic solvents
composed of C, H, O
differ from carbohydrates due to LESS oxygen
can have other elements (P,N)
Are unsaturated fatty acids liquids or solids at room temp.?
liquids at room temp (oils)
Functions of lipids
energy reserves
insulation
increases buoyancy
example of lipids
phospholipids
Do higher latitude plants have MORE or less unsaturated fatty acids than lower-latitude plants?
have more
i.e. less energy
could be due to temp. conditions
Characteristics of carbohydrates
C, H, O
building blocks for polysaccharides (cellulose, glycogen)
components of other molecules (DNA, RNA, ATP, glycoproteins)
general formula – (CH2O)n
What are the bonds that join monosaccharides together?
glycosidic bonds
Functions of carbohydrates
source of energy for body (glucose)
store of energy (e.g. starch in plants)
Differences between cellulose, starch, & glycogen
cellulose: unbranched
starch: branched, less regular branches than glycogen; a-1,4 glycosidic –> limits # of H bonds that can form
glycogen: branched; bound to 3 glucose molecules; both at a-1,4 & a-1,6
Order of compactness
- cellulose
- glycogen
- starch
Characteristics of nucleic acids
DNA
nucleotides
RNA
both form long, linear chains that never branch
composed of base, phosphate, & ribose / deoxyribose
Which direction to nucleotides bind?
5’ to 3’ direction
What is the bond that forms between nucleotides called?
Phosphodiester bond
Functions of proteins
- most functionally diverse of all biomolecules
enzymatic proteins
defensive proteins
storage, transport, receptor, hormonal etc.
What are the building blocks of proteins?
amino acids
What is the bond that form between amino acids called?
peptide bond
Primary proteins
unique sequence of amino acids
Secondary proteins
due to H bonds
coil = a-helix
folded = B-pleated sheets
Tertiary proteins
due to R groups
disulphide bridges, H-bonds, ionic bonds, hydrophobic interactions
Quaternary proteins
when 2 or more polypeptide chains form 1 macromolecule e.g. haemoglobin or collagen
Which biomolecules are seen with electron microscope?
atoms, small molecules
viruses
proteins
lipids
Which biomolecules are seen with a light microscope?
chloroplast
most bacteria
cells
What caused the Great Oxygenation event?
photosynthetic cyanobacteria – thin ozone layer formed
protected life from UV radiation
allowed life to move from oceans to land
What is the cell wall of prokaryotes composed of?
peptidoglycan – protein coated sugar (is the target of antibiotics)
Gram positive bacteria
- cell-wall: less complex
- more peptidoglycan
- less toxin
- cell wall = thicker (retain the stain & look purple)
Gram negative bacteria
- cell wall: more complex
- outer membrane contains lipopolysaccharides
- more toxic
cell wall = thinner (does not retain stain & looks pink)
What is mycoplasma?
smallest prokaryotic organism
pathogenic to humans
lack a cell wall
resistant to antibiotics
What is the size of prokaryotes?
range from 1 micrometre to 10 micrometres
What are endospores?
found in ancient crystals
- contain DNA
- formation triggered by lack of nutrients
- gram-positive bacteria
resistant to harsh conditions
What is the growth type of prokaryotes?
exponential growth
Outline binary fission
- single circular molecule of DNA attaches to specific point on plasma membrane
- DNA replicates
- DNA attaches to dif. point of plasma membrane
- plasma membrane will grow inwards
quick replication = ?
huge biodiversity
Benefits of prokaryotes
- used for recycling (clean up waste water)
- GM bacteria (genetically modified) make many pharmaceuticals e.g. human insulin
- used to make GM plants e.g. more nutrients
why do some archaea have a phospholipid MONOLAYER?
- MORE STABLE SYSTEMS
How much larger are eukaryotes than prokaryotes?
3 - 4 x
What is the first eukaryotic found?
Grypania spiralis fossils (2.1 B years old)
- contains eukaryotic biomarkers - fatty acids and was isolated in ancient oil
What us a chromosome made up of?
each chromosome is made up of material called chromatin - a complex of proteins & DNA
Where does glycolysis happen?
in the cytosol of a cell (outside mitochondrion)
Where does the Krebs cycle happen?
intermembrane space of mitochondria
What are plastids?
photosynthetic organelles in plant cells
How may the nucleus have formed?
from invaginations of the plasma membrane around the nucleoid of an ancient prokaryote
Where did mitochondria arise from?
the primary endosymbiosis of purple bacteria
- formed a relationship w/ aerobic bacterial cell
Where are mitochondria found?
animals
fungi
What are the origins of chloroplasts?
arose from primary endosymbiosis of photosynthetic cyanobacteria
Where are chloroplasts found?
green algae
plants
Evidence for endosymbiosis
- these organelles appear morphologically similar to bacteria
- surrounded y outer membrane similar to cell membrane
- are semi-autonomous 9/retaining their own genome i.e. DNA)
- have their own machinery for synthesizing proteins, including ribosomes
- their metabolism is like existing prokaryotic organisms
- the chloroplasts in some species still have the bacterial peptidoglycan wall b/w the inner 7 outer membrane e.g. Cyanophora
What is secondary (or eukaryotic) endosymbiosis?
a chloroplast derived from an ENDOSYMBIOTIC EUKAROYTIC CELL rather than a prokaryote
- 3 or 4 membranes around chloroplast
another eukaryotic cell engulfs the first one
