module 1 Flashcards
Describe the main compoenets of lipids and its functions
Composed mainly of c, h and o that can readily dissolve in organic solution but is insoluble in water.
Can contain other elements such as phosphorus and nitrogen
Differ from carbohydrate in having a smaller proportion of oxygen
Exist as long chain fatty acid or triglycerides
Solid/semi-solid when saturated and liquid when unsaturated
Functions: energy reserves, insulation (eg blubber in marine animals helps store energy, insulate and increase buoyancy)
Examples:
Membrane lipids/phospholipids: two fatty acids (saturated and unsatureated) bound to a glycerol
Phosphate group on the head allows it to be hydrophilic and thus be able t osit in a soluble environment
Describe main components of carbohydrates
Molecular compounds composed of carbon, hydrogen, and oxygen
a source and storage of energy that can be components of other molecules and building blocks for polysaccharides
Monosaccharides: glyceraldehyde, ribose, deoxyribose, manrose, galactose and fructose - draw monosaccharides
Ribose has an oxygen whereas deoxy doesn’t
Glycosidic bond union of two
Cellulose os single chain causing strong fibrous structure whereas starch and glycogen are branched
Starch have less occurring branches with glucose on carbon 6
Glycogen more frequently occurring branch cause it to be more compact
Bonding affecting structure and function
Describe main components of nucleic acids
DNA, RNA bith are pentose sugars but RNA has a n oxygen on the second carbon
Four nucleotides: pyrimidines - adenine and thymine,
purines - cytosine and guanine - double ring structure
Bind in a 5’ to 3’ direction -
Nucleotides: building blocks of nucleic acids - consists of a base, irbose/deoxyrible and phosphate - pyrines bind to pyrimidines
Rna can form shapes - hydrogen bonds between nucleotides
mRNA, tRNA, rRNA
Carbon
Fundamental element for all major biomolecules
Glucose as primary energy source
Define PCR and outline its process
Amplification of dna
1. Denatureation: heated to 94-98 to separated double stranded dnastrands
2. Annealing: 55-72 to allow primers to bind to complementary strands of dna
3. Extension : 68-72 enzyme extends the primer by incorporation
Good primer pairs are created by having similar lengths and percentafe G and C bases (%Gc)
Outline 4 different structures of proteins
Primary: sequence of amino acids - dictate function of protein’
Secondary: beta-pleated sheat and aloha helices - interaction between backbone
Teriary: interaction between r groups
Quaternary: to or more polypeptide chains
Differentiate between gram positive and gram negative
Gram positive: bacteria containing more peptidoglycan, making it structurally less complex with a thicker cell wall. They are less toxic and retain the stain making them look purple
Gram negative: bacteria with a more structurally complex cell wall with an outer membrane containing lipopolysaccharides. More toxic, with a thinner cell wall and does not retain dye in gram stain
What happened in the great oxygenation event
- Early earth atmosphere has zero oxygen, high co2, ammonia, methane and intense radiation
- Photosynthesis of blue-green algae (cyanobacteria) initiated oxygen production involving the photochemical dissociation of oxygen from water before binding with another oxygen molecule to form O2
- Accumulation of oxygen created the ozone layer, protecting earth from the sun’s radiation
- When the ozone layer thick enough, there was a massive diversification of life where complex cellular organisms began to evolve in the ocean to become mobile and live in shallower parts of the ocean while still undergoing photosynthesis. This is also known as the cambrian explosion
- Selurian period: Ozone high enough for organisms to live on land
- Oxygen is a highly reactive gas ans therefore didnot accumulate in the form of o2 until it had interacted with all the compound in the earth’s system
What component of prokaryotic cells allow it to be useful in medicinal practices
Most bacteria produce a cell wall composed of a macromolecule called peptidoglycan, a protein coated sugar- -amino sugars with short peptide attached
Human cells don’t contain peptidoglycan and therefore is a useful target when making antibiotics
Penicillin works by preventing the final cross-linking step in peptidoglycan, causing the cell wall to not form. This result in a cell to be fragile and eventually die
Why is mycoplasma a concern in the medicinal industry
Mycoplasma are a concern as most are pathogenic to human due to the lack of a cell wall and therefore a lack of peptidoglycan a major .. in which most antibiotics target. Instead of a cell wall is has a rigid plasma membrane rich in sterols and lipoglycnas
What is the relationship between cell size and cell efficiency
- Smaller cells is more effective at transporting materials compared to larger cells as there is a larger surface area for nutrients to be absorbed and secrete waste products
- Energetic penalties for large cells - transporting molecules in and out
- Larger cells require more phospholipids to biosynthesize to make up the plasma membrane anf peptidoglycan for the cell wall
What are endospores
-Dormant, tough, reproductive structure in prokaryotes
-Contains dipicolinic acid (compound that helps increase heat resistance)
-Found in gram positive bacteria
-Formation triggered by lack of nutrients
-Can undergo exponential growth
-Rapid generation period
-Undergo binary fission
Prokaryote vs eukaryotic diversity
Prokaryotes have a faster generation period and therefore increasing the frequency of spontaneous mutation occurring and thus a larger biochemical diversity when compared to eukaryotics
Ribosomes
Made up of two subunits; rRNA and proteins
Responsible for protein synthesis (Rough ER and cytosol for eukaryotes/ cytosol for prokaryotes
Eukaryotic ribosomes are larger, more rRNA and contain more and different ones in a cell
Targeting prokaryotic ribsomes in drug target
How is archaea different from bacteria
Archaea’s genetic transcription is more similar to eukaryotes compared to bacteria
Have unusual lipid and membranes and lack a peptidoglycan wall
Can be found in many different environments
Not found in resting spores and are not pathogenic
Differ from both groups in biochemical, structural features, genetic
Ether linked cell wall
Multiple rna polymerase
Trna is methenamine, formal methenamine-baceria , methenamine - eukarytpe
Many are thermophilic and acidophilic
Lists the evidence for the endosymbiotic origin of mitochondria and chloroplast
Both morphologically similar to bacteria
Surrounded by an outer membrane similar to cell membrane and inner membrane invaginates to from lanellae
Both are semi-autonomous - contains their own genome - similar to bacterial dna
Can divide independently
Own machinery to synthesise proteins
Metabolism is similar to existing prokaryotic organisms
Chloroplasts in some species still have the bacterial peptidoglycan wall between inner and outer memebrane!!
What is endosymbiosis and explain its process
What is secondary endosymbiosis
Involves the engulfing of a cell which has gone through primary endosymbiosis. This results in more than two sets of membranes surrounding the chloroplasts
Endoplasmic reticulum
Consists of membrane cisternae (flatten membrane)
Plasmodesmata
Large surface to volume ratio
Synthesis of proteins, glycoproteins, carbohydrates and lipids
golgi apparatus
System of polar membrane cisternae called golgi stacks and are responsible for the collection, packaging and distribution of molecules
Mostly recieves vesicles from the ER which enters via the cis face and exits via the trans face
lysosome
Single membrane organsims known to be the ‘recycle bins’ of a cell as it is invovles in breaking down abnormal or waste material (even pathogens) via endocytosis. It has an acidic interior
vacuole
Plays a similar role as lysosomes in plants with its main role being a storage for nutrients, pigments and in plants, maintain their turgor structure. It also has hydrolytic enzymes
Microbodies
Are single membrane organelles which contain enzymes
There are two types: peroxisomes (break down amino acids) nad glyoxysomes (break down fatty acids)
Single membrane and have enzymes derived from free ribosomes in the cytoplasm
Neutral pH, oxidative enzymes the generate h2o2 and catalase to break down h2o2
Two types: peroxisomes (break down amino acids) and glyoxysomes (break own fatty acids)
Process of protein synthesis
- mRNA molecule provides the transcript for the production of a specific protein and travels out the nucleus and into a ribosome located on the rough ER
- Ribsome transcribes the mRNA, resulting in the formation of a protein
- Protein is then exported via a transport vesicle to the golgi apparatus to undergo modifications to produce a fuctional protein
- Protein is packaged into a vesicle before combining with the membrane and exported out the cell via exocytosis
What is the cytoskeleton and list the 3 components its made of
Made up of proteins; microtubules, microfilaments and intermediate filament that act together to allow structural stability and shape of the cell as well as facilitate cell movement
