2.2.1-2.2.2 Study Guide

2.2.1-2.2.2 Review

What does MRI stand for?

Magnetic Resonance Imaging

Define an MRI (use definition in my.pltw)

A medical imaging technique that uses magnetic fields and radio waves to take pictures of the soft tissues of the body

What is mitosis?

Mitosis involves the doubling and separation of genetic material and results in the formation of two new nuclei

Why is mitosis important? 3

Mitosis is important because cells need to reproduce for a variety of reasons including

1. replacing a cell that dies

2. healing a wound

3. when the body goes through a growth spurt

What are the 5 stages of mitosis? (IPMAT+)

1. Interphase

2. Prophase

3. Metaphase

4. Anaphase

5. Telophase + cytokinesis

In what phase of mitosis does DNA condense into chromosomes?

Prophase

In what stage(s) of mitosis are there two new cells?

Telophase + cytokinesis

How are tumors connected to mitosis?

Mitosis is a highly regulated event, but there are times when this process goes unchecked and leads to uncontrolled cell division. This uncontrollable cell division can cause the formation of tumors.

What is cancer?

A disease caused when cells divide uncontrollably and spread into other tissues

Tumors are examined by *_.* This helps to determine if the tumor can be classified as _ or _. If it’s cancerous it will be considered _ . The cancer invades other tissues or parts of the body through _.

Tumors are examined by __BIOPSY__. This helps to determine if the tumor can be classified as __BENIGN__ or __MALIGNANT__. If it's cancerous it will be considered __MALIGNANT__. The cancer invades other tissues or parts of the body through __METASTASIS__.

What is a biopsy?

A biopsy is the removal of cells or tissues from a patient’s body using a needle, scalpel, or other tools to study them more closely using a microscope

What are mutations?

Changes to a DNA sequence

How do mutations affect DNA?

Mutations affect DNA because it causes a change in the sequence which causes a change to the amino acids used to make proteins. This can cause something different to be made.

Proteins are the building blocks of _

Life

What does protein synthesis do?

Protein synthesis creates new proteins

What are the two steps of protein synthesis?

1. Transcription

2. Translation

Describe what happens during transcription

During transcription DNA is copied into RNA

Describe what happens during translation

During translation RNA is read (in groups of 3 called codons) and specific amino acids are used to make proteins

RNA is read in groups of _

Three

There are *_* and _ codons. These are codes that start and stop translation/the creation of a protein.

There are __START__ and __STOP__ codons. These are codes that start and stop translation/ the creation of a protein.

DNA: G A C C G A T A C C A T T C G G C G C A T A C T T C C, transcribe the DNA into RNA.

RNA: C U G G C U __A U G__ __G U A__ __A G C__ __C G C__ __G U A__ __U G A__ A G G

RNA: C U G G C U __A U G__ __G U A__ __A G C__ __C G C__ __G U A__ __U G A__ A G G, translate the RNA using your codon chart.

Amino Acids: methionine, valine, serine, arginine, valine, STOP

What will happen to the protein if there is a change to the DNA sequence? 4

1. No longer function

2. Have reduced function

3. Have increased function

4. Be different and have a different function

What are the 3 types of mutations in DNA?

1. Insertion

2. Deletion

3. Substitution

Compare the DNA sequences to the normal sequence. Label and circle/highlight where there is a mutation.

Substitution (C→T), Insertion (+C), Deletion (-A)

Transcribe the DNA sequences:

a. TAC TAT GCC TTA

b. TAC TTC AAA ATC

a. TAC TAT GCC TTA → RNA: AUG AUA CGG AAU

b. TAC TTC AAA ATC → RNA: AUG AAG UUU UAG

Make a mutation of your choice to the original DNA sequence. Label and highlight where the mutation is.

**ORIGINAL**

DNA: TAC TAT G==**C**==C TTA → RNA: AUG AUA CGG AAU

TRANSLATION: methionine, isoleucine, arginine, asparagine

\
**MUTATED (insertion of the letter T)**

DNA: TAC TAT G==**T**==C CTT A → RNA: AUG AUA CAG GAA U

TRANSLATION: methionine, isoleucine, *glutamine, glutamic acid*

Describe the change that was made and the effect it had on the protein.

The letter T was INSERTED into the sequence. This caused all the letters after the mutation to slide over. This caused new codons to be made. The sequence now has glutamine and glutamic acid instead of arginine and asparagine. This mutation caused new amino acids to be used in the making of this protein which can cause a different protein to be made all together.

Translate the RNA sequences: 

\
a. RNA: AUG AUA CGG AAU

b. RNA: AUG AAG UUU UAG

a. methionine, isoleucine, arginine, asparagine

b. methionine, lysine, phenyl-alanine, STOP