Module 4.3 Proteins Flashcards
Proteins are the most abundant of all the
biomolecules
Proteins are essential for all
living organisms including bacteria, plants and animals.
What shapes can proteins have?
Proteins can be globular, tubular, or stringy, among other wide variety of shapes.
List some functions of proteins.
- Enzymes
- Hair
- Muscle fibers
- Hormones
- Antibodies
Amino acids are
monomers are protein
What are the monomers of proteins?
Amino acids are the monomers of proteins.
How many different amino acids are there?
There are 20 different amino acids.
Each amino acid is given a
3 letter designation
What is the three-letter designation for serine?
Ser
What is the three-letter designation for methionine?
Met
What is the three-letter designation for alanine?
Ala
Amino acid naming typically end in
-ine
Define essential amino acids.
Essential amino acids are those humans need in their diet. We can’t make these ourselves.
Define non-essential amino acids.
Non-essential amino acids are those humans can make in their cells.
What groups do all amino acids have?
- Amino group
- Carboxyl group
- R (variable) group
- Hydrogen
Amino Acid Structure
Amino Acids always have a
Central Carbon with a Hydrogen attached to it. It will also have an amino group (n) and a carboxyl groups (double bonded 0)
What is always different in an amino acid structure?
The R group. It can be extra carbons, ring structures, just about anything. This is the difference when it comes to functionality
What happens to amino acids in solution?
The acidic carboxyl group donates its H+ to the basic amino group, resulting in a positively charged amino end and a negatively charged carboxyl end.
What is the R group of an amino acid?
The R group is variable and differs from one amino acid to another.
List the four types of R groups in amino acids.
- Non-polar and hydrophobic
- Polar and hydrophilic
- Acidic and hydrophilic
- Basic and hydrophilic
Acidic and basic amino acids are
ionic and charged in solutions
Amino acids are linked by the
dehydration reaction
What is a peptide bond?
A peptide bond is the covalent bond that forms between amino acids after/during? a dehydration reaction
What is a dipeptide?
A dipeptide is 2 amino acids connected by a peptide bond.
What is a peptide?
A peptide is made up of less than 50 amino acids.
What is a polypeptide?
A polypeptide is larger than 50 amino acids and is called a protein when it folds.
Once a peptide or polypeptide folds, it is called a
protein
If proteins loose it’s shape or structure, it can loose it’s
functionality
What is the hydrolysis reaction in the context of digestion of proteins in our stomach?
The hydrolysis reaction is used to break down proteins into its amino acids.
What determines the function of a protein?
The structure of the protein determines its function.
The long chain of amino acids, the polypeptide, is like a ribbon and begins to fold into its
characteristic shape that will determine the structure of the protein
Protein misfolding can create
problems
What are the four levels of protein structure?
- Primary
- Secondary
- Tertiary
- Quaternary
What characterizes primary protein structure?
The sequence of amino acids held together by covalent bonds. Looks like a necklace
What characterizes secondary protein structure?
Folding of part of primary structure into curly-hue (alpha helix) or zigzag (beta pleated sheets) held together by weak hydrogen bonds.
What characterizes tertiary protein structure?
Folding of polypeptide into its 3D shape held together by interactions of R groups.
What characterizes quaternary protein structure?
Interaction between 2 or more polypeptides held together with bonds of the backbone and R groups.
What percentage of our protein is made from 3 polypeptides in a triple helix?
40% of our protein is made from 3 polypeptides in a triple helix
The misfolding of proteins often occurs when
the wrong amino acid is inserted into the primary structure
What diseases are associated with misfolded proteins?
Diseases such as Alzheimer’s and Parkinson’s are associated with misfolded proteins.
What is denaturation?
Denaturation is when the shape of a protein is destroyed, thus destroying its function.
What factors can denature proteins?
- Temperature
- pH
- Salt concentration
What happens to egg white proteins when cooked?
Heating denatures the proteins, turning them from clear to white.
How does pH affect proteins?
Acidic or basic environments can denature proteins.
What is the space-filling model of proteins?
It shows atoms that make up the protein.
What does the ribbon model of proteins illustrate?
It shows alpha helix structures and beta pleated sheets.
What does the 3-D (‘Blob’) model of proteins show?
It shows the overall shape of a protein and its polypeptides.
