Studied by 22 peopleWhat cells contain DNA?
All cells
What do genes carry?
Instructions that code for formation of proteins
What are specialized cell functions carried out by?
The proteins they produce
For the cell to function properly,
the protein must function properly
What is the function of DNA
To carry instructions that organisms need to survive, develop, and reproduce.
What is the difference between DNA and chromosomes
Genes are segments of DNA, chromosomes contain genes.
A < - > (In DNA)
T
G < - > (In DNA)
C
A < - > (In RNA)
U
G < - > (In RNA)
C
DNA -- >
RNA
RNA -- >
Amino Acids
Amino Acids -- >
Proteins
What genes do brain cells have?
All of them
What gene will brain cells express?
What is needed for that cell to function
What determines a function of a protein?
It's shape and order of amino acids. (A changed shape/out of order amino acid may slow down or stop the proteins function)
What determines how a protein is made?
It's sequence of amino acids
DNA (Transcription) - >
mRNA
mRNA (Translation) - >
Amino Acids
Amino Acids - >
Proteins
When is a gene expressed?
As it's needed
When would lactase be made?
When lactose is consumed
Introns
Non-coding, they are cut out in translation
Exons
These are expressed and put together.
What is the role of non-coding sections?
Controlling gene activity
What does a histone do?
Coils DNA
How does acetylation affect gene expression?
Relaxes the DNA, which allows the RNA polymerase to bind (increases gene expression)
How does methylation affect gene expression
Tightens the DNA, RNA polymerase can't bind. (Inhibits expression)
What allows gene expression to take place/increase speed?
Positive transcription factors, acetylation, high rna polymerase affinity.
What inhibits gene expression?
Negative transcription factors, methylation, mRNA destroyer
How does the environment affect gene expression
Food, drugs, exposure to toxins and more can change how your genes are expressed. THIS DOES NOT CHANGE THE ACTUAL DNA
What is your epigenome?
What affects gene expression from your environment
What do epigenetic changes do to your DNA?
Nothing
What's a point mutation?
A single base substituted.
What's a silent mutation?
When the mutated codon codes for the same amino acid. This has no effect
What is a missense mutation?
When the mutated codon codes for a different amino acid. The effect varies (ie. sickle cell anemia)
What is a nonsense mutation?
When the base change results in an early stop codon. This is usually very serious.
What is a frameshift mutation?
Insertion or deletion, causes a change in the reading frame.
CRISPR
Genetic 'scissors' used to cut out a defective gene
Gene therapy
Using viruses to introduce healthy genes into the human genome
Exon Skipping
When introns are cut out of the mRNA, an exon coding for a disease may also be cut
RNA interface
RNA is used to 'attack' and cut out mRNA strands that may code for a disorder, essentially silencing the gene.
Gene Switches
A way to interfere with the non-coding or regulatory sections of DNA that may code for a disease
Small molecule therapy
Drugs that interact and interfere with a disease causing protein.
What parts of a gene do not appear in the final mRNA
Introns, start serquence, and stop sequence
What end products of DNA are not proteins?
RNA, Introns, and regulatory sequences.
What does histone modification affect?
Whether a gene can be expressed or not.
How many genes are in human DNA?
25,000
How many different proteins are produced?
Up to 1 million
How can many proteins be produced from few genes?
Post translational modification and Splicing
Promoter
where RNA polymerase attaches, signaling the start of a gene
Operator
Where a repressor binds, stopping the transcription of that gene
Structural Genes
genes coding for the enzyme, they are transcribed as a unit
How is transcription of lactase enabled in the presence of lactose?
The repressor binds to the operator when lactose is not present, but in the presence the repressor is released.
Hemophillia
Blood clotting proteins don't work
Sickle Cell
blood cells are shaped wrong
Cystic fibrosis
faulty protein in the cell membrane
Androgen insensitivity
faulty receptor for androgens, appears in females
Note
Flashcard