Welcome to Dr. Kate Brilakis' Learning Portal
The sequence of the amino acids determines how those amino acids interact with one another which determines how the protein folds which determines its final shape/structure.
Structure/shape of a protein determines its Function!
Most biological processes have ALOT of "steps" and
each step is facilitated by a different enzyme.
the chemistry of organic molecules
nucleic acids
they differ based on how their glucose monomers are bonded together.
Tay Sachs Disease
the substrate must "fit into"
the activation site of the enzyme
3 or more monosaccharides bonded together = a polysaccharide
(C6H12O6)n = polysaccharide
2 monomers bonded together (C6H12O6)2 = a disaccharide
This is a triglyceride
see how the enzyme names often end in ase.
the name suggests the process that enzyme is affecting
an enzyme will exhibit a
"lock and key specificity
with its substrate.
besides triglcerides, lipids include sterols and waxes.
other enzymes can break down polymers releasing monomers =
catabolic reaction
Enzymes
<- this disaccharide is lactose
(milk sugar) made by bonding
one glucose to one galactose
single bond double bond
C - C C = C
ex: lactase breaks down lactose
ex: transaminases move amino groups from
one molecule to another.
what is a gene?
genes are specific DNA sequences
enzyme activity can be regulated by inhibitors.
Why would regulation be necessary?
sterols have a four ring structure. an example is cholesterol.
hydrolysis
polymers are broken into monomers.
water is added.
H2O = H + OH
a bond between two monomers is broken.
the bond sites are satisfied with the addition of an H to one monomer and an OH to the other monomer.
some amino acids are considered essential =we can't build them ourselves in our cells, while others are non-essential = we can build these
a specific gene "codes" for a specific protein by serving as the instruction book to select and assemble amino acids in a particular order
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there are four different
versions of this nucleotide used to build
DNA: A,T,C,G
Here is the formula for a general enzymatic reaction:
enzyme
substrate -------------------> product
proteins
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there are four types of organic molecules
Here is the formula for a catabolic (degradative) enzymatic reaction:
enzyme
substrate -------------------> product + product
there are 20 different amino acids. these 20 different types of amino acids are the same except for their R group.
the "R" group determines to which of the 20 amino acid groups that amino acid belongs.
OMG super important!!
here are the 20 different amino acids --->
the R group that each amino acid possesses give that
amino acid certain characteristics that affect how it
behaves around other amino acids..
Adenine
Thymine
Cytosine
Guanine
many amino acids bonded together forms a chain called a polypeptide
more about enzymes later in
this section ;)
so what is a protein?
lipids
more inhibitors present = less product
fewer inhibitors present = more product
Phospholipids:
made from one glycerol, TWO fatty acids and one phosphate group. Phospholipids make up all cell membranes
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mutations may lead to a change in how the amino acids are lined up when the cell makes a protein.
if the amino acid sequence is wrong, the chain of amino acids will fold differently causing the protein to have a different shape. this different shape may cause the function of the protein to be different ior the protein to not work at all.
some fatty acids exhibit double bonds between their carbons
amino acids have an amine group, a carboxylic acid group and an R group.
carbohydrates
#C atoms
<- this disaccharide is sucrose
(table sugar) made by bonding
together fructose and glucose
what is a phospholipid?
DNA and RNA are polymers.
these polymers are made from monomers called nucleotides
A HEXA gene mutation causes a deficiency of the enzyme beta-hexosaminidase A (hex A).
Hex A is necessary for the break down of a fat called GM2 ganglioside found in the brain.
without this enzyme present,
the ganglioside accumulates and damages the brain.
but what if the sequence of the DNA of a specific gene is "different" from what it is supposed t o be? now we have a mutation!
types of polysaccharides are:
waxes are made from fatty acids and alcohol.
covalent bond
if the sequence of the amino acids determines the structure and function of a protein,
what determines the sequence of the amino acids?
DNA!
RNA is another type of nucleic acid polymer made from nucleotide monomers. RNA serves as a go between in the process of making proteins.
RNA's monomers are similar to DNA's monomers BUT not the same.
fyi: what are trans fats or
partially hydrogenated fats?
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questions to consider:
1. What is a monomer? a polymer?
Complete this chart:
monomer (s) polymer
polysaccharide
triglyceride
protein
nucleic acid
2. What is the formula for glucose?
3. How is starch structurally difference from cellulose?
Why does this matter in biological systems?
4. How many different versions of amino acids are there? ____
Each of these versions of amino acids is different because each has a different ___________.
5. What is meant by the term essential amino acid?
6. Explain why the sequence in which amino acids are bonded together is important.
Explain what might happen if this sequence is incorrect.
7. What makes a triglyceride saturated?
Explain why saturated triglycerides are considered a less "healthy" food choice.
8. What is the function of dehydration synthesis?
Explain how this process is different from the process of hydrolysis.
9. Why are enzymes sooooooo important?
10. What is an anabolic reaction? Are anabolic reactions endergonic or exergonic?
Explain your answer.
11. What is the function of DNA?
12. Another nucleic acid is RNA. What is RNA's job?
13. What is a gene?
14. If there is a mutation in a gene, why might this affect the function of a the protein?
15. What is a phospholipid? Why are these polymers so important?
3. nucleic acids
Here is the formula for an anabolic (synthetic) enzymatic reaction:
enzyme
substrate + substrate -------------------> product
these two processes are used to create and degrade
lipids, carbohydrates, proteins and nucleic acids
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1. Carbohydrates
are you lactose "intolerant"?
if so, you do not synthesize lactase, the enzyme that breaks down lactose.
RNA's nucleotide monomers are
A, U, C, G.
U is used instead of T
and the sugar of RNA nucleotides is ribose.
many pathologies occur when there are deficiencies in enzyme production such as...
protein folding has four stages:
primary
secondary
tertiary
quartenary
carbohydrate monomers are
monosaccharides
why is the enzyme name above the arrow?
A only pairs with T
C only pairs with G
a nucleotide is hydrogen bonded to its partner in the center (rungs) of the ladder
dehydration synthesis
monomers bond together to form polymers by removing
an H from one monomer and an OH from the other.
water (H2O)is formed
H + OH = H2O
the molecules bond can then together at the empty bonding sites.
each of our cells contain 3 billion base pairs of DNA. this DNA in every cell is over 3 feet long and is divided into 46 chromosomes.
the sequence of DNA's nucleotides determines the sequence of the amino acids of the protein. DNA is like a cookbook telling the cell which amino acids to select and in what order to arrange them to make a protein.
the monomers used to make proteins are called amino acids. amino acids are also called peptides (kinda old timey)
anabolic reactions are endergonic.
endergonic reactions absorb energy.
enzymes
facilitate chemical reactions, allowing them to occur faster while using less energy
<- these three molecules all have the same formula but different atomic arrangement. they are therefore considered isomers of one another
how are organic polymers made
and how are they broken down??
glucose (C6H12O6)
is a monosaccharide
but also fructose and galactose
for example: sickle cell disease
catabolic reactions are exergonic. Exergonic reactions release energy.
Lipids are made from two different types of monomers:
1 glycerol monomer
3 fatty acid monomers
enzymes
are protein catalysts that exhibit an activation site that can bind to a substrate and cause the substrate to be modified into a product.
4. Lipids (fats)
double C bonds cause the fatty acid to exhibit a kink in its structure. this makes it easier for the body to break down and process.
the glycerol is always the same but the three fatty acids can be different. It's the types of fatty acids that are bonded to the glycerol that determine what type of fat it will be
fyi:
trans fats not only raise LDL ("bad") cholesterol levels (as saturated fats also do), they also lower levels of HDL ("good") cholesterol.
forces occur between amino acids in a polypeptide that cause the polypeptide bend and twist into a 3D shape.
enzymes can build polymers from monomers = anabolic reactions
amino acids are bonded together via covalent bonds called peptide bonds
2. Proteins
these nucleotides are arranged in pairs along a double stranded DNA polymer which resembles a ladder.
a mutation = an error in the DNA sequence
enzymes lower a reaction's activation energy