Exam 4 Flashcards
What happens in gene regulation and chromatin?
Tightly packed means genes are hidden and not available (Heterochromatin) and loosely packed means genes are not hidden and available (Euchromatin)
What groups tighten chromatin and what groups loosen them?
Acetylation group = loosens chromatin
Phosphorylation group = loosens chromatin
Methylation group = condenses chromatin
How are genes expressed when there is a lot of methylation, not a lot of methylation, and when there is a normal amount of methylation?
More methylation = no expression
Less or no methylation = high expression
Normal amount of methylation (some methylation) = normal expression
What are specialized transcription factors?
They enhance the activity of the gene or silence it, they do not bind to the promoter. Either bind before the promoter or after the promoter
What are general specialized transcription factors?
They do the same thing and bind to the promoter
What do activators do in gene expressions?
Enhance gene expressions
What is RNA splicing?
Where two mRNAs are made.
What are exons?
They are a sequence in RNA that are not cut out and are coding regions. They code for a specific domain
What introns?
They are a sequence in RNA that are cut out. They are non coding regions, and have potential to be codons.
What are the exons and introns in the transcript A mRNA and transcript B mRNA? (look at pic in your phone)
Transcript A
Exon 3 = Exon
Exon 4 = Intron
Transcript B
Exon 3 = Intron
Exon 4 = Exon
What is the initiation of translation?
Where ribosomes bind to the start codon on mRNA and does it’s translation process
What are regulatory proteins in the initiation of translation?
They bind to the 5 prime untranslated region (UTR) which prevents the ribosome from binding
What is life-span of mRNA in the initiation of translation?
Proteins that bind to the 3 prime UTR that initiate destructions
What does short life and long life mean?
Short life = quick response to environmental changes
Long life = long-term expression
What is protein processing?
Where proteins are in the inactive form and need certain actions to be activated again.
What is cleavage in protein processing?
the process of breaking the peptide bonds between amino acids in proteins
What is longevity of proteins in protein processing?
adding of ubiquitin to a protein and destroys it
What are some other molecular groups that you add to help with protein processing?
adding of phosphate and sugar groups to the proteins
What is the function of non-coding RNAs?
Bind to the mRNA
They block translation
Degradation (destroys) of target DNA
What are some examples of non-coding RNAs?
MicroRNAs (miRNA)
Small interfering RNAs (siRNAs)
How does cell division happen in bacteria?
Chromosome replication begins at the origin of replication
Then they go around in a circle
Origins of each new chromosome anchor to the cell membrane at opposite sides
Cell growth pulls chromosomes to opposite sides
Cell divides
What stage are most of the cells in our body in? And what happens with the cells in this stage?
G0, They carry out normal functions, not preparing for division
Why does a eukaryotic cell enter the cell cycle?
Grow
Repair
Reproduce
What is the G1 stage? And what happens to the cells that are in this stage?
Undergo intense metabolic activity and grow
Makes everything needed for DNA synthesis
Typical time 5-6 hours
What is the S phase? And what happens to the cells in that are in this phase?
DNA replication happens
Typical time 10-12 hours
What is the G2 stage? And what happens to the cells that are in this stage?
Cell growth
Makes all materials needed for cell division (phospholipids, microtubules, proteins, enzymes
Typical time 4-6 hours
What does the G stand for in the cell cycle?
Gap
What is the M stage? And what happens to the cells that are in this stage?
Where mitosis and cytokinesis take place
What is mitosis? And what happens during it?
Chromosomes condense (spaghetti like structure to being packets of ramen)
The nuclear membrane is going to break down
Chromosomes will line up in the center and be connected but then they will move to opposite sides of the cell
Occurs in distinct stages
What are sister chromatids?
opposite chromosomes and attract to each other
What is the prophase in mitosis?
Duplicated chromosomes condense and sister chromatids join in the center
Mitotic spindle (microtubules) begins to form
What is the prometaphase in mitosis?
Nuclear membrane is broken down
Chromosomes condense more
Mitotic spindle connects with the chromosomes in the center
What is the metaphase in mitosis?
Chromosomes align in the center
Sister chromatids attached to the microtubules on opposite sides/poles
What is the anaphase in mitosis?
Sister chromatids separate
Chromosomes move to opposite sides of the cell
What is the telophase in mitosis?
Nuclear membrane reforms
Chromosomes become less condenses
Microtubules disappear
Cleave furrow forms
What happens after mitosis?
Cytokinesis begins
What happens during cytokinesis?
Cleavage furrow constricts
Cell divides
Cells separate
What are the stages in the interphase stage?
G1, G2, S phase
What did Payton Rous do a study on in 1911?
Studied chickens and their tumors