9671753
Description
Flashcards by Hannah Hercher, updated more than 1 year ago
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Created by Hannah Hercher
over 6 years ago
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| Question | Answer |
| Topic 2 | Molecular Biology |
| 2.1 Molecules to metabolism Molecule | smallest part of a compound, which has the chemical properties of that compound !! Elements exist in ionic compounds!! |
| anions and cations | anion - negatively charged -> gained electron cation - positively charged -> lost electron |
| electrophilic atom | electrophilic - loves water |
| Bonding | ionic - looses electrons ionic bonds - one atom looses e- the other gains the e- covalent - shares electrons polar covalent binding - sharing electrons. The atom that's more electrophilic pulls other atom closer |
| Polar Covalent bonds (eg) | |
| Glycerol | |
| Types of carbon - based compounds | polymers - many units monomers - one unit many attached monomers make up one polymer |
| Anabolism vs Catabolism | Anabolism - synthesis of new compounds (make macromolecules from monomers) A+B->AB Catabolism - makes smaller molecules from macromolecules AB->A+B |
| Glucose Alpha vs Glucose Beta | |
| Condensation reaction | Names for it: Condensation reaction, synthesis reaction or dehydration reaction looses/produces one water molecule |
| Hydrolisis | break- down of water |
| dimer and tetramer | two( monomers) up to ten then it's a polymer tetramer - 4 |
| Hydrolysis reaction | Names for it: Hydrolysis reaction or decomposition reaction (water included in reaction) |
| Polypeptide | many AA's (amino acids) attached to another also: polypeptide - many smaller molecules that make up proteins/long chains of AA's. |
| Difference polypeptide and protein | usually (not always) a protein is made of several polypeptides hence: monomer of proteins - > AA's |
| Proteomics | Functions of proteins - Defense -Communication - Structure -Enzymes -Transport -storage |
| Proteome | a collection of proteins produced by a cell, tissue or organism - tells you what you are predisposed to e.g. breast cancer |
| Enzymes |
Most enzymes are proteins
They are biological catalysts (speeding up reactions) AND are not changed by the reaction
Image:
45 (binary/octet-stream)
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| Structure of DNA & RNA | - DNA & RNA molecules are polymers - their monomers are called: nucleotides |
| Nucleotides | consist of: * a pentose sugar (Deoxyribose in DNA) * a phosphate group (acidic + negatively charged) * a nitrogenous base - Adenine (A) -Guanine (G) -Cytosine (C) -Thymine (T) |
| DNA base pairing Guanine and Cytosine | |
| DNA base pairing Adenine and Thymine | |
| DNA replication, transcription and translation | |
| Replication | DNA copying -happens in the synthesis (s phase) of interphase |
| Experiment: Meselson & Stahl Background | - carried out in 1958 which supported the hypothesis that DNA replication was semiconservative - when the double stranded DNA helix is replicated, each of the two new double-stranded DNA helices consisted of one strand from the original helix and one new one - nitrogen is found in the nitrogenous bases of each nucleotide, they decided to use an isotope of nitrogen to distinguish between parent and newly copied DNA. The isotope of nitrogen had an extra neutron in the nucleus, which made it heavier.(N15) E. coli was grown for several generations in a medium containing NH4Cl with 15N. When DNA is extracted from these cells and centrifuged on a salt (CsCl) density gradient, the DNA separates out at the point at which its density equals that of the salt solution. The DNA of the cells grown in 15N medium had a higher density than cells grown in normal 14N medium. After that, E. coli cells with only 15N in their DNA were transferred to a 14N medium and were allowed to divide; the progress of cell division was monitored by microscopic cell counts |
| Experiment: Meselson & Stahl Procedure | - nitrogen is found in the nitrogenous bases of each nucleotide, they decided to use an isotope of nitrogen to distinguish between parent and newly copied DNA. The isotope of nitrogen had an extra neutron in the nucleus, which made it heavier.(N15) E. coli was grown for several generations in a medium containing NH4Cl with 15N. When DNA is extracted from these cells and centrifuged on a salt (CsCl) density gradient, the DNA separates out at the point at which its density equals that of the salt solution. |
| Experiment: Meselson & Stahl Results | The DNA of the cells grown in 15N medium had a higher density than cells grown in normal 14N medium. After that, E. coli cells with only 15N in their DNA were transferred to a 14N medium and were allowed to divide; the progress of cell division was monitored by microscopic cell counts |
| Experiment: Meselson & Stahl Results cont. | DNA was compared to pure 14N DNA and 15N DNA. After one replication, the DNA was found to have intermediate density. Since conservative replication would result in equal amounts of DNA of the higher and lower densities (but no DNA of an intermediate density), conservative replication was excluded. However, this result was consistent with both semiconservative and dispersive replication. Semiconservative replication would result in double-stranded DNA with one strand of 15N DNA, and one of 14N DNA DNA from cells after two replications had been completed was found to consist of equal amounts of DNA with two different densities, one corresponding to the intermediate density of DNA of cells grown for only one division in 14N medium, the other corresponding to DNA from cells grown exclusively in 15N medium. This was consistent with semi conservative replication |
| Replication (detail) | DNA-> DNA - starts at origin of replication site - Helicase unwinds DNA helix (unzips) creating a fork - single strand binding proteins stabilize 2 separate strands of DNA. Needed because of: elastic potential energy -> snaps back when released - Primase - adds primer where DNA Polymerase can start - DNA polymerase adds nucleotides |
| Replication Fork | |
| Lagging strand vs Leading strand | lagging strand - 3' - 5' direction leading strand - 5' - 3' direction |
| Transcription | DNA->RNA - similar to replication - RNA polymerase unwinds the DNA strand so that the base sequence can be copied -RNA polymerizes the RNA nucleotides in order for those two things to BE POSSIBLE RNA polymerase must first combine with a promoter - RNA (which includes mRNA) is a single stranded molecule hence, only ONE of the two DNA strands will be used as a template to create the mRNA molecule |
| Transcription visualized | |
| Complementary Base pairing differences! | everything remains the same binding EXCEPT: Adenine (A) on the DNA is now paired with Uracil (U) on the newly forming mRNA molecule |
| IMPORTANT -> Transcription | only one of the two strands of DNA is copied the other strand is not used |
| Cell respiration (book definition) | making energy in the form of ATP by mitochondria takes place in EVERY cell in our body! |
| Cell respiration (syllabus definition) | controlled release of energy from organic compounds to produce ATP |
| ATP | Adenosine Tri Phosphate - negatively charged |
| Aerobic respiration | Produces: 36 ATP/Gluc net: 2ATP/Gluc WITH oxygen |
| Anaerobic respiration | WITHOUT oxygen Alcoholic Fermentation Glucose-> ethanol + CO2 Lactic Acid Fermentation Glucose-> lactic acid (causes oxygen debt) - regulated breathing needs oxygen to break down the lactic acid (oxidizing) lactic acid ->> HARMFUL |
| Glycolysis | breaks down glucose into pyruvate Glyco - glucose lysis - break- down Needs to happen in order for respiration to take place |
| Bioethanol | - bacteria used to ferment wastes - ethanol produced - renewable energy source |
| Bioreactor | manufactured or engineered device or system that supports a biologically active environment |
| Photosynthesis | production of carbon compounds in cells using light energy |
| Chlorophyll (photosynthesis) | - chlorophyll absorbs red and blue light most effectively and reflects green light more than other colours |
| Visible light | visible light has a range of wavelengths with violet being the shortest and red the longest wavelength |
| Photolysis of water | break - down of water to give oxygen (to provide for electrons) happens from energy of photons |
| Gaffron's Experiment |
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