Gene Expressions

HLB Gene Expression Test

What 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