B200 - Study guides, Class notes & Summaries

Describe how H3Lys9me heterochromatin is formed ~~> H3Lys9me heterochromatin formation: Lys9 deacetylated by HDAC. Suvar39 then methylates lys9. Methylated lys9 is recognised by HP1 and then HP1 binds. HP1 has chromodomain - chromodomains often recognise and bind to methylated lys residues. Chromodomain on HP1 is specific for H3Lys9me (with di or tri methylated lys 9). Binding of HP1 is thought to compact nucleosome arrays as HP1s join together. What is gene expression? ~~> ...

Eukaryotic promoters have a basal region which can contain a TATA box, initiator (Lnr), BRE (TFIIV recognition element) and what other element? ~~> Downstream core promoter (DPE) In prokaryotes RNA polymerase requires what co-factor? ~~> 70 sigma factor Forms the holoenzyme The promoter is formed of two hexameric sequences at what positions? ~~> -35 and -10 The amount of product transcribed is dependant on how close the promoter sequences are to what? ~~> Consensus s...

What are the 4 sources of infection? ~~> Bacteria, viruses, fungi, parasites What does the immune system need to be able to do for an effective immune response? ~~> 1- Be able to recognise and respond to any invading organism 2- Not over react to benign or self 3- Be able to direct different effector mechanisms against different pathogens approximately how many bacteria are their and how many are named? ~~> 10^9 bacteria and 30000 named What is specific/adaptive immunity? ~...

Pathogens that may infect mammals can include fungi, bacteria, viruses as well as large, multi-cellular organisms such as ~~> helminths The first phase of an immune response is known as as the innate response with the second phase called the ~~> acquired/adaptive The acquired phase is specific and relies on the detection of infectious agents using ~~> .receptors expressed by lymphocytes The process by which enough cells expressing receptors for the correct pathogen is know...

Why does RNA degradation take place? ~~> Damaged mRNA Incorrectly transcribed/processed mRNA Control gene expression What 2 things control mRNA levels? ~~> Transcription and turnover Why is turnover important? ~~> If mRNA has a ridiculously long half life and doesn't go away, then if you stop transcription you don't stop protein expression because the mRNA is still there Describe what casein mRNA is and explain the importance of turnover ~~> Expressed in mammar...

CMB2001 EXAM QUESTIONS AND VERIFIED ANSWERS..

Are B and T lymphocytes part of the adaptive or innate immune response? ~~> Adaptive it is the immune memory evolved over time What is the clonal selection theory? ~~> Immature lymphocytes that could self find are destroyed Mature naive lymphocytes are mature until they are exposed to antigens What are the two types of B receptor? ~~> Membrane bound And released from membrane they are known as antibodies T cell receptors are only membrane bound and are formed of what hete...

he tissue layer of cells lining the inner wall of the abdomen and pelvis What is systemic sepsis? - answerThe presence of bacteria in other tissue of the body What are ureters? - answerA tube that carries urine down from the kidney to the bladder What is the vermiform appendix? - answerA small outpouching from the beginning of the large intestine What does superior mean? - answerNearer to head What does inferior mean? - answerNearer to feet What does anterior mean? - answerNearer to fron...

What is a pathogen? ~~> A microorganism that causes disease e.g. bacteria, fungi, virus, parasite For an effective immune response the immune system must... ~~> - be able to recognise and respond to any invading organism - not over react to benign or self - be able to direct different effector mechanisms against different pathogens What is specific/adaptive immunity? ~~> - it is induced by exposure to a particular infection - shows a high degree of specificity - exhib...

Core Promoter Elements ~~> TATA box = repetitive sequence of thymine and adenine Initiator (INR) = sequence of pyramidines like thymine and cytosine DPE = downstream promoter elements found along the DNA Common to have >1 promoter but not all of them CpG islands ~~> Sequences high in CG frequency. They are able to escape methylation which would lead to gene silencing. Demethylation would lead to over expression of genes. Regulatory Promoter Elements ~~> UAS and URS f...