Nerve activates contraction

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Transcript Nerve activates contraction

Proteins:
what’s so special about them?
Today, we will talk about….
1. what are Proteins made of
2. what gives Proteins their characteristics
3. what are some of the major functions
of proteins
So, our first goal…
What are Proteins made of?
Proteins are
polymers
•What does that mean?
What are the monomers of Proteins?
• All proteins are made from a common set of 20 kinds of amino acids
• Amino Acids (AA) are the monomers of Proteins.
• They have weird names like….
• Methionine
• Isoluciene
• Histidine
• Threonine
• Glutamine
• Amino acids are bonded to other amino acids by peptide bonds
A bit about Amino Acids…
• Three parts of an amino acid…
• 1. Carboxyl group
• 2. Amino group
• 3. Side group
• The side group is what makes amino acids different from
each other!
• AA are bonded to other AA by dehydration synthesis,
making “peptide bonds”
Copyright © 2009 Ekis, Inc., Tell Glenn to shand up Publishing
Dehydration Synthesis….
Peptide bond
Water is
given off!
Copyright © 2009 Ekis, Inc., Bring me Macaroons Publishing
What is an “essential Amino Acid”?
• We have the ability to make 12 of the 20
amino acids needed to build proteins
• However, there are 8 that we must consume….
Phenylalanine, valine, threonine,
tryptophan, isoleucine, methionine,
leucine, and lysine.
The Amino Acids (AA) are arranged in a long
chain, then the chain folds. This new shape
enables it to function.
Peptide
Bonds!
AA
AA
AA
AA
AA
AA
AA
AA
AA
AA
AA
AA
AA
AA
AA
AA
AA
AA
AA
AA
AA
AA
This whole thing would be a Protein!!
Sometimes known as a “Polypeptide”…
Important concept alert!!!
Every protein can
only fold a specific way
, so if you need a specific type of
fold (for a specific function or
ability), you have to make a
specific type of protein!!
Now, our second goal…
What gives Proteins their
characteristics?
In other words: what enables proteins
to fold certain ways?
If YOU were to build a protein model (stick
a bunch of AA together to create a protein),
what could you do that would make your
protein unique compared to everyone
else’s??
•
Change The type of Amino Acids make the protein
unique
•
Change the number of Amino Acids make the protein
unique
•
Change the order of Amino Acids make the protein
unique
These three things are what mainly determine a protein’s
characteristics!
Example of how one small difference
can cause HUGE changes…
Hemoglobin - an important protein used by red blood
cells to transport Oxygen throughout the body.
It is 146 Amino Acids long!!
BUT, If you replace Glutamic acid (AA) with Valine (AA) at the
sixth position, the hemoglobin cannot fold correctly.
This ultimately causes red blood cells to have a funky
shape….
Normal
Sickle Cell Anemia
Big Question…
What do you think determines
the order, number, and type of
amino acids used by the
ribosome to build proteins???
•DNA!!
Now, our Third goal for today…
What are some of the major functions
of proteins?
1. Movement
•
Also known as contractile proteins: actin
and myosin
•
Create the structures in muscle cells that allow contraction
2. Structure
•
Collagen
•
Most abundant protein in the body.
•
Forms connective fibers like ligaments, tendons, cartilage,
etc.
3. Transport
• Within body
• Hemoglobin
• Moves Oxygen (O2) throughout the body
• Red blood cells are FILLLED with hemoglobin!!
4. Regulation
• Hormones!!
• Important in homeostasis
• Used to signal cell to cell
• Send messages throughout the body
• Produced by glands
• Insulin
• Regulates blood sugar level
• Diabetes
5. Defense
• Antibodies
• Cover receptor sites on bacteria/viruses
• Prevents them from attaching to YOUR cells!
• Clumps them together so HUGE white blood cells
can engulf and destroy them in large numbers
• Can you name this process of engulfing them in
large numbers?????
Endocytosis - Phagocytosis!