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Biology Journal 9/16/2014. 2.4 Homework Quiz!. True or false: Amino acids are bonded together in long chains by what are known as peptide bonds. True or false: The sequence of amino acids for a protein is found on code of the DNA.
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Biology Journal 9/16/2014 2.4 Homework Quiz! • True or false: Amino acids are bonded together in long chains by what are known as peptide bonds. • True or false: The sequence of amino acids for a protein is found on code of the DNA. • How many different kinds of amino acids are used by ribosomes to make proteins? • What is a proteome?
Review! a. What kind of molecule is this? b. What are its parts called? It’s an amino acid! (this one is called asparagine) R group (in this case CH2CONH2) Amine (NH2) Carboxyl (COOH) Alpha carbon (the middle C where the R group is attached)
Protein and Amino Acids • Proteins do everything! • Protein makes skin stretchy, bones tough, gives your body parts their color, lets you digest different foods, makes up hormones, creates your immune system …
Proteins are 1 chain of amino acids (sometimes multiple), that fold up into specific shapes based on the chemical properties of the amino acids.
Generalized Amino Acid How many amino acids make up this polypeptide?
Ribosomes: part of the cell that makes proteins from an RNA copy of the DNA code. They join amino acids together with peptide bonds. What do ribosomes do?
There are infinite possibilities of proteins! They can be any length, and any combination of amino acids. Turns garbage into bacon Your welcome.
We can break down proteins we eat to get energy / amino acids.
Proteins can irreversibly lose their specific shape through a process called denaturing. Causes: • Changes in temperature • Changes in pH Denaturing
Proteome: The set of all of the proteins an organism makes. DNA in 23 chromosomes Transcribed into mRNA Genome Translated into an amino acid sequence by ribosomes Proteome Folds into proteins Polypeptide Every individual has its own unique genome which leads to its own unique proteome
Proteins do everything! Such as… Motor Proteins: They move, allowing cells to change shape. Muscle cells are packed with these.
Proteins do everything! Such as… Transport Proteins: These are proteins stuck in the cell membrane that let specific substances in or out of your cells.
Proteins do everything! Such as… Receptor Proteins: These are proteins stuck in the cell membrane that are used for cells to communicate with eachother.
Proteins do everything! Such as… • Your immune system tells the difference between “self” and “non-self” by these receptors.
Blood types are an example of receptor proteins . • The blood types are: A, B, AB and O • Doctors killed a lot of dogs before they figured this one out…
Muscles are made of protein. Meat is high in protein because meat is animal muscle.
There are many ways of representing proteins DNA Helicase Simplified model
There are many ways of representing proteins DNA Helicase Space-filling model
There are many ways of representing proteins DNA Helicase Model showing -helixes and -sheets.
20 amino acids bonded together in different orders can form all proteins. What do proteins do? Everything! The function of the protein is defined by its shape.
20 amino acids bonded together in different orders can form all proteins. Fibrous Long, insoluble proteins Parallel polypeptide chains Cross-linked Spider Silk
20 amino acids bonded together in different orders can form all proteins. Globular Folded, compact polypeptide chains Almost spherical shapes Rubisco Rhodopsin Insulin Immunoglobulin
Denaturation A process that destroys the complex structure of a protein. • Heat • Strong acids • Strong alkalis New structure = new function Denaturation of an egg protein
Proteomics DNA in 23 chromosomes Transcribed into mRNA Genome Translated into an amino acid sequence by ribosomes Proteome Folds into proteins Polypeptide Every individual has its own unique genome which leads to its own unique proteome
A chemical reaction is shown below. Name each reactant and product. What kind of reaction is this? Where should water be present in the reaction? How many molecules of water? Review! Catabolic Hydrolysis Reaction Monopeptide (amino acid) Monopeptide (amino acid) Dipeptide → + H2O • Hydrolysis (water is split) • It “fills in” each monomer
A chemical reaction is shown below. Name each reactant and product. What kind of reaction is this? Where should water be present in the reaction? How many molecules of water? →
A chemical reaction is shown below. Name each reactant and product. What kind of reaction is this? Where should water be present in the reaction? How many molecules of water? Catabolic Hydrolysis Reaction Monopeptide (amino acid) Monopeptide (amino acid) Dipeptide → + H2O • Hydrolysis (water is split) • It “fills in” each monomer
DNA has the “recipe” to make proteins. A gene is a segment of DNA that has the instructions to make a particular protein. “Hmmm… how many teaspoons of cytosine was I supposed to add?”
The base pairs on DNA determine the amino acids, and thus the specific shape, that the protein will have.
For example… we all have genes for hair color. The base pairs on this DNA determines what proteins are in our hair, and thus, what our hair looks like. Of course, you can always change it later…
What does it mean to be a translator? What does it mean to transcribe something?
When does your body need to make different kinds of proteins?
Transcription and translation is done every time a cell makes a protein. So, almost every cell in your body is doing this all the time! Above: the structural protein collagen. This poor guy will be making lots of it soon to repair his body.
Ancient Egypt was well known for its scribes that made copies of documents. Nowadays we don’t really need them, we have copy machines…
Transcription is making a copy of the DNA onto mRNA (messenger RNA). The enzyme that makes it is called RNA polymerase. Some people transcribe their homework all the time.
mRNA is a temporary, disposable copy of DNA. It’s sent from the nucleus to the ribosome. DNA is permanent. You don’t want to change or mess with it. RNA is a disposable copy.