Term
| RNA polymerase reads which strand and in what direction during transcription? What direction do ribosomes read mRNA? |
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Definition
The template strand, 3' to 5'
Ribosomes read mRNA 5' to 3' |
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Term
Name and describe the levels of protein structure
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Definition
Primary - amino acid sequence
Secondary - helixes and shapes (a and b)
Tertiary - single subunit
Quaternary - all subunits |
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Term
| What is the central dogma? |
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Definition
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Term
| The amount of the four DNA bases (A,G,C,T) are all different, true or false? |
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Definition
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Term
| DNA always contains 50 percent purine and 50 percent pyridimine bases, true or false? |
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Definition
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Term
| Explain the semiconservative model of DNA replication |
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Definition
| Shows that when DNA is stained, the daughter cells contain one copy each of the original strand and its replited compliment. One of the following daughter cells will be completely made of replicated DNA (won't contain strand from original cell) |
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Term
| What stabilises individual DNA strands during unwinding so they can't bind back together? |
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Definition
| single-strand binding proteins |
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Term
| Explain the process of okazaki fragments |
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Definition
| Made on lagging strand because of reading direction, constant RNA primers being put down so polymerase can make the fragment. The RNA primers are removed by DNAPOL I and DNA Ligase joins them together |
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Term
| What are the two main types of bacteria and their membrane characteristics? |
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Definition
Gram-positive - Positive stain: thick layer of peptidoglycan on outside
Gram-negative - Negative stain: Thin layer of peptidoglycan in between membranes |
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Term
| First and second law of thermodynamics? |
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Definition
1 - cannot be destroyed
2 - increase entropy
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Term
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Definition
| Delta final state - Delta initial state |
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Term
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Definition
Anabolism - building molecules
Catabolism - Breaks down |
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Term
| What must cells do to make endergonic reactions proceed? |
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Definition
| Couple them with exergonic reactions |
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Term
| What's the formula for cellular respiration and its delta G? What happens as a result of such a large exergonic reaction? |
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Definition
C6H12O6 + 6O2 > 6CO2 + 6H2O + ENERGY
-638 kcal/mol
Would explode so we release it in small steps |
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Term
| What is oxidised and what is reduced in cellular respiration? |
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Definition
| Carbon atoms are oxidised, Oxygen is reduced |
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Term
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Definition
| Enables oxidised compounds to become much more reduced |
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Term
| What are the two parts of a gene? |
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Definition
| The coding region and the control region (promoter, enhancers etc) |
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Term
| Each nucleosome consists of how many histone proteins? |
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Definition
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Term
| What does an operon consist of? And in what order? |
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Definition
1 - Promoter
2 - Operator (On/off switch)
3 - Genes for proteins that work together |
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Term
| When is LacL repressor bound to the Lac operon? When is it removed and what by? |
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Definition
| In the absence of lactose/allolactose. Removed by allolactose when lactose is present |
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Term
| Describe positive and negative control in the lac operon |
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Definition
Negative: lacL repressor on operon, is removed in presence of lactose BUT
Positive: cyclic AMP levels must be high enough that CAP binds upstream of promoter, otherwise will only get weak transcription (cyclic AMP levels are high when glucose is low) |
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Term
| Discuss repression and inducibility in operons |
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Definition
Inducibility: lac operon, transcription induced by presence of lactose
Repression: Trp operon, always on until excess tryptophan turns it off. |
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Term
| What are the levels of regulation in eukaryotic cells? |
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Definition
Inside nucleus: Chromatin remodelling, transcriptional control, RNA processing (5'-3' capping, polyadenylation, splicing)
Outside nucleus: RNA localisation, RNA stability and degradation, translational control, protein folding and post-translational modification |
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Term
| No promoter, no transcription. True or false? |
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Definition
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Term
| Discuss how splicing can contribute to genetic regulation |
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Definition
| Different or non-sequential exons from the same gene can be spliced together to give rise to different mRNA's/proteins |
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Term
What is the role of miRNA?
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Definition
| Post transcriptional gene slicing through cap and tail removal of targeted mRNA, allowing it to degrade |
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Term
| What is the function of the virus capsid |
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Definition
Mechanical damage (shearing)
Chemical damage (UV)
Enzymatic damage |
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Term
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Definition
| Obligate intracellular parasites |
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Term
| What are the stages of a viruses life cycle? |
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Definition
Attachment
Penetration
Uncoating
Transcription/translation
Genome replication
Assembly
Release
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Term
How and why do viruses break the rules of the central dogma? Explain how polio does it vs HIV
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Definition
+ and - sense RNA, negative has to be transformed into + sense before it can act as mRNA.
Polio: ssRNA + sense, makes - sense copy which acts as template for + sense replicates
HIV: ssRNA + sense, retrovirus (integrates into hosts genome and lives as provirus), makes DNA to integrate through reverse transcriptase |
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Term
| In meiosis, which division is unique and which is just like mitosis? |
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Definition
| The first is unique (seperates homologous pairs making daughter cells haploid), second division is just like mitosis |
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Term
| When does crossing over occur? |
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Definition
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Term
| Why did Mendel exceed with his pea experiments? |
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Definition
peas were a good model system
focussed on all or none characters
studied inheritance of one trait at a time
made observations over three generations
kept accurate quantitative records |
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