biology test 2

tertiary sources

(1) articles in a newspaper (NY Times) or magazine written by identified journalists. Rarely contain complete citations. (2) Government warnings as consumer updates. (3) Encyclopedia entries such as Wikipedia that contain some citations and references, but the content of the article may or may not have been fact checked.

how changes to the epigenome can be responsible for cancer

Certain chemicals consumed can overstimulate the porto-oncogenes which result in rapid reproduction of cells.

CRAP test

Currency, Reliability, Authority, Purpose/Point of View

how microarrays are produced and used to detect differences in gene expression between cells

DNA microarray is a technique that scientists use to determine whether genes are on or off. Microarray analysis involves breaking open a cell, isolating its genetic contents, identifying all the genes that are turned on in that particular cell, and generating a list of those genes.

how chromatin structure or chemical modification of DNA (known as epigenetics) affects gene expression

Epigenetics is the study of heritable changes in gene expression (active versus inactive genes) that do not involve changes to the underlying DNA sequence — a change in phenotype without a change in genotype — which in turn affects how cells read the genes.

how chemotherapy drugs might take advantage of methylation to re-activate gene

It methylates the parts of the gene that shouldn't be expressed so it suppresses that gene. It stops tumor growth if it methylates the thing that was causing the growth.

PU test

P= check for Previous work U= go Upstream/ laterally from the source

Epigenome

The epigenome is made up of chemical compounds and proteins that can attach to DNA and direct such actions as turning genes on or off, controlling the production of proteins in particular cells. when epigenetic compounds attach to DNA and modify its function, they are said to have "marked" the genome.

regulatory proteins def and their role in adding tags to the epigenome

a gene regulatory proteins attach to a specific sequence of DNA on one or more genes. once there, it acts like a switch, activating gene transcription or shutting them down

micro ray- explain what color spots you would expect to see for genes that are expressed in normal cells or over-expressed or under-expressed in cancer cells

colors: red- it is bound to gene that is expressed more frequently in a cancerous cell green- it is bound to a gene that is expressed more frequently in normal cells yellow- it is bound to a gene that is expressed more frequently in both types of cells (cancerous, normal) grey- it is bound to a gene that is not expressed in either type of cells (cancerous, normal)

example of how epigenetic changes can occur in response to the environment

epigenetic regulation has to do with the genes passed down tp you from your parents. Part of it is inheritance and the other part is the environment - if you have a nurturing environment ... mouse experiment. What you eat, if it has methyl or acetyl groups in it can affect it.

different cells have different functions & characteristics but are genetically identical b/c..

every cell has the exact same genes and DNA. depending on the location of the cell, the histones are either methylated (tightly wrapped) or acetylated (loosely wrapped) which allows them to express their specific function.

how epigenome affects your cells

example: the Agouti Mouse model

when "epigenetic regulation" normally occurs and why

it occurs by adding either methylation histones or acetylation histones. methylation histones wind the DNA up more (which makes DNA unreadable for transcription) and Acetylation histones unwind the DNA (which makes DNA readable for transcription)

protein involved in winding DNA into chromatin

methyl makes it more tightly wound and turns it off acetyl makes it more loosely wound and turns it on making it open to transcription

difference between active and inactive genes in terms of chromatin winding and chemical modifications (methylation and acetylation)

more methyl- more tightly wound : inactive more acetyl- less tightly wound: active

primary sources

research studies performed, written and then submitted for peer-review to a scientific journal that build upon and include references to previous studies (original data)

secondary sources

reviews of several research studies written up as a summary article with references. can appear in peer-reviewed academic journals or government