Connect! Why does DNA remain in the nucleus? What are the two jobs of DNA?

Connect!

• Why does DNA remain in the nucleus?

• What are the two jobs of DNA?

Putting it Together: DNA Functions

•Genes are Chemical Instructions

A gene is a length of DNA. DNA is a long list of instructions on how to put the organism together and make it work.

Each separate gene is a specific chemical instruction to a particular type of cell.

Cells make proteins by stringing amino acids together in a particular order.

There are only about 20 different amino acids but they make up millions of different proteins.

Genes simply tell cells what order to put the amino acids together. The sequence of bases or order determines what proteins the cell produces, which in turn determines what type of cell it is, for example skin cell or nerve cell.

How Does DNA Control A Cell?

Sequence of bases in a gene

Sequence of amino acids

Shape of protein

Type of cell and activities it carries out

Collagen is a protein found in bones, tendons and cartilage, so it needs to be strong.

The chains are tightly coiled to form a strong, fibrous structure.

It is formed by bone and cartilage cells using a specific collagen gene, which is a specific sequence of bases, which produce a specific sequence of amino acids, which fold into a specific shape…the twisted, chain of collagen. The shape gives the protein its function.

Insulin is a hormone that reduces blood glucose levels.

It’s a small, globular protein, so it is easily transported in the blood.

It is formed by pancreas cells using a specific insulin gene, which is a specific sequence of bases, which produce a specific sequence of amino acids, which fold into a specific shape…the small, glob of insulin. The shape gives the protein its function.

Chunk!•What are the 2 functions of DNA?

•What is a gene?

•What kind of instructions are encoded in the DNA?

•How do cells make proteins?

•What do genes “tell” the cell?

•What does the sequence of bases determine?

•What does the sequence of amino acids determine?

•What does the shape of the protein determine?

•How does DNA control a cell?•Explain, using either collagen or insulin as an example.•How do organisms end up with different types of cells?

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Dog genes!