PROTEINS

The final product of the DNA blueprint

Hemoglobin

Why are proteins important?

“When the body has something it needs to do, it is a protein that does it” http://www.rothamsted.ac.uk/notebook/courses/guide/prot.htm

Antibodies – fight disease

Why are proteins important?

“When the body has something it needs to do, it is a protein that does it” http://www.rothamsted.ac.uk/notebook/courses/guide/prot.htm

Receptors – part of cell membrane, interacts with outside of cell and tells cell what’s happening

Why are proteins important?

“When the body has something it needs to do, it is a protein that does it” http://www.rothamsted.ac.uk/notebook/courses/guide/prot.htm

Enzymes – assemble or digestEnzyme that digests insulin

Why are proteins important?

“When the body has something it needs to do, it is a protein that does it” http://www.rothamsted.ac.uk/notebook/courses/guide/prot.htm

Neurotransmitters and hormones – bind to receptors to trigger a response

Neurotransmitters

Why are proteins important?

Channels and pores – allow large molecules to pass through cell membranes

What determines the role or function of a protein?

Shape – click for examples

What determines the shape of a protein?

Amino acids are building blocks of proteins

AminoGroup

AcidGroup

What determines the shape of a protein?

B. 20 different amino acids each with their own R group

Each “R” group gives amino acids their . . .

- size

- shape

- charge

- Preference for water (hydrophobic or hydrophilic)

Amino acids are connected by peptide bonds

What determines the shape of a protein?

Primary Structure – Sequence of amino acids.

Four levels of structure (Just FYI)

Secondary Structure – some chains form an alpha helix (coil) or a beta sheet (accordion).

Four levels of structure

Tertiary Structure – How all of the helices and sheets fold together.

Four levels of structure

Quaternary Structure – some proteins are made of more than one subunit.

Four levels of structure

Summary – How the protein folds is determined by thetype and number of amino acids used.

How does the body know how to make proteins?

A.DNA sequence.

B. If nucleotide order is changed:

- sequence of amino acids is changed.

- Shape of protein is different.

- Protein loses function.

Cystic Fibrosis Video – “Cracking the Code” Chapter 9 )

Genetic Testing VideoCLICK HERE -

http://topics.nytimes.com/top/news/national/series/dnaage/index.html - WATCH “When a DNA Test Shows a Lethal Fate”