Transcription
During transcription, one gene is copied from DNA into an RNA molecule, which is referred to as...
mRNA
What is the process of translation?
Where does it make its product?
when an mRNA strand is used as a template to construct a protein in ribosomes
What are somatic cells? Give 3 examples
Body cells (skin, muscle, hair, heart, nerve, bone)
What are three parts of the cytoskeleton?
Flagella, cilia, and centrioles
What is a mutation?
What causes them? What is one example?
A change to an organism’s DNA
Exposure to mutagens, such as radiation, chemicals, and viruses
What is a segment of DNA that codes for a protein called?
Gene
How does the mRNA fit into the ribosome to be translated?
In what increments is mRNA translated?
the ribosome will move along the mRNA, which fits in between these two subunits
the ribosome reads a strand of mRNA three bases at a time, which are called codons
Why do different cell types make different proteins and have different structures?
Proteins determine the specialized function and the structure aids the completion of that function
What does the nucleus do (2)?
Where are ribosomes made in the nucleus?
stores DNA and carries out transcription
Ribosomes are made in the nucleolus
What are the four main type of genetic mutations?
insertion, deletion, duplication, and inversion
What is enzyme that carries out the synthesis of RNA during transcription?
How does it work, and in what direction?
RNA polymerase
It separates each strand of DNA and uses one strand as a template to make RNA one base at a time in the 5’ → 3’ direction
What is the purpose of codons like AUG and UAG?
AUG codes for Met, telling the ribosome to begin translating
UAG codes for a stop codon, ending translation
What is cellular differentiation?
What are undifferentiated cells that can renew themselves through cell division indefinitely? Can it be reversed?
the process by which these cells become specialized
stem cells, cannot be reversed
What are the main two organelles that process and package proteins so they are ready to be used by the cell?
What do they look like?
The rough endoplasmic reticulum and the golgi apparatus
Look like a stack of hollow tubes
How are somatic cells and germ cells different?
What is the difference in how mutations spread in somatic cells and germ cells?
somatic cells-body, germ cells- sperm/egg
mutations in body cells spread to daughter cells
a mutation in germ cells can be inherited in the next generation
Where does RNA Polymerase begin and end the process of transcription?
promoter (start)
terminator (end)
What does tRNA do?
How does tRNA know where to bind to mRNA?
tRNA carries the amino acids to the ribosome
tRNA molecules have an anticodon on the end that is complementary to a codon on the mRNA
What is gene expression?
By which process does it occur?
There are two primary types of genes in terms of expression, those that are on/off, what are they called?
Gene expression refers to the activation (turning ON) of certain genes in a cell
through transcription
active- expressed gene
Genes that are not used and turned off- silenced gene.
What is the difference between a ribosome and lysosome?
Which four codons code for Valine?
If a mutation happened where one codon mutated into the other, which type of mutation would this be since the amino acid remains the same? Why?
GUU, GUC, GUA, GUG
Silent mutation because the mutation has no effect on the organism
What are introns, splicing, and exons?
Why are a 5’ cap and poly-A tail beneficial for mRNA?
Where does this take place in the cell?
non-coding portions - introns
splicing- removal of introns
exons- parts that are kept in the final mRNA
the 5’ cap and poly-A tail help protect the mRNA from degradation and assist in initiation of translation
Occurs in the nucleus
What do ribosomes catalyze the formation of?
What does tRNA do after it has dropped off its amino acid?
the peptide bond between the amino acids
the tRNA leaves the ribosome to pick up another amino acid in the cytoplasm.
How is gene expression modified in cells?
Give two examples and explain the process.
DNA Methylation - The addition of a methyl (-CH3) group to cytosine bases in the promoters will turn off transcription. This prevents the gene from being used.
Histone Acetylation - The addition of acetyl groups to histone proteins results in the chromatin fibers becoming “loose”. This allows RNA polymerase to get access to the DNA and will generally turn transcription ON.
What is the difference between smooth endoplasmic reticulum and rough endoplasmic reticulum?
(Function and structure)
smooth endoplasmic reticulum - a series of tubes and sacs that make all of the lipids for the cell
Rough endoplasmic reticulum - a series of tubes and sacs that are studded with ribosomes - helps fold and process proteins, packages into vesicles to send to the golgi apparatus
GCAATGTTACGGAGC ----> GCAATCTTCACGGAGC
What are the two types of mutations that took place?
How do you know?
Insertion and Frameshift mutation