Chapter 3, Proteins Flashcards
What are the 5 elements that are found in proteins
Hydrogen,Carbon,Nitrogen,Oxygen,Sulfur
What is the general terms for the monomers of proteins
The building blocks of proteins
Amino Acids
How many different amino acids are used in human proteins
There are 20 amino acids for the human body
What is the general term for polymers of proteins
What is the protein chains called
Polypetides
What are the 6 important functions of proteins in the body
Catalysts, Defence, Movement, Signalling,Structure,Transport
Describe these 6 protein functions in the human body
Catalyst: Speeds up chemical reactions (Enzymes)
Defence: Antibodies attack pathogens
Movement: Move cells or molecules (Human tissues or cell projections)
Signalling: Convey signals between cells (Chpt 6b-f/11)
Strucuture: Shape cells and comprises the body strucuture (Chpt 6b-f/11)
Transport: Allows molecules to enter/exit cell or carry them through out the body (Chpt 6b-f/11) (Prumps,channels and exchangers)
Comprises = make up
What two functional groups are amino acids made from
Carboxyl (COO-) and Amino (NH2+) functional groups
What type of molecules are amino acids
Organic molecules
How are amino acids have unique properties compared to each other
They contain different side chains which are knownas R-groups
What is an α-carbon
Central carbon that is connected to two functional groups in an amino acid
How would you draw an amino acid
Start off with central carbon. Add Amino group and Carboxyl group to the sides. Add an H group to the top and add an R group at the bottom
How many types of amino acids are there
4
Uncharged Polar, Nonpolar,
Charged Acidic(-) and Basic (+)
Amino acids can be grouped from the properties of the side chains.
How can you tell the difference between the types of amino acids
If there is a negative charged O- group, it is ACIDIC
If there is amino/nitro group (2 NH group or NH2, or NH3+ group), it is BASIC
IF there is an non charged O group (C=O or R-OH) then it is uncharged POLAR
If there is non of the following or contains sulfur, it is NON POLAR
What happens to amino acids in water
The functional groups inoize to NH3+ and COO-, allowsing them to stay dissolvedi n solution and the amino acds to be more reactive
How do amino acids polymerize
Amino acids polymerize when:
A bond forms between a carboxyl group of one amino acid to another amino group the other amino acid
What bond is between the two monomers of amino acids
The bond between the C-N is called a peptide bond
What is N-termius and C-terminus of an amino acid
N-termius = Starting the amino acid chain, ALWAYS starts with an AMINO group
C-terminus=Ending the chain, ALWAYS ends with a carboxyl group
Why is the flexibility of the amino acid chain important?
The flexibility of the c-c bonds allows the amino acids to fold into 3-D proteins shapes
An “Blank” is a polymer of less than 50 amino acids
“Oligopeptide”
An “Blank” is a polymer of more than 50 amino acids
“Polypeptide”
Proteins can be used to refer to what amino acid chain
To any amino acid chains, but more formally refers to the complete,functional form of the molecule
Each protein has a unique linear “blank” of amino acids
“Sequence”
Proteins have unparalleled divesity of what?
of size,shape and chemical properties
How is the 3-D shape of a protein determined and what does the shape do?
The sequence of amino acids determines a protein’s 3-D structure. It’s structure determines if function
From Q25
What type of structure does this represent
A primary protein structure
What is an example of the shape of a protein being important to its function
An enzyme
How is the primary structure of a protein determined
By our genetic code (DNA)
What is the central dogma
It is our main method of transporting genetic information into usable proteins and components (DNA -> RNA -> Proteins)
What strucuture is fundamental for higher levels of protein structure and why?
Primary structures, The amino acid R-groups affect a polypeptide’s properties and functions.
A single amino acid change can radically alter protein function
What is characterisic of proteins
Each has a charcteristic folded shape, which is neccsary for its function and shape is ALWAYS related to function
How is a protein’s secondary structure formed? And what situation must be satisfed for this secondary structure to form
A protein’s seconadary structure is formed by hydrogen bonds between two amino acids. Can only occur when a polypeptide bends so that C=O and N-H GROUP of the BACKBONE are close together to form H-bonds
HINT :Secondary structure is created by BACKBONE H-BONDS
What are the two major types of secondary structures
α-helix (Alpha)
β-pleated sheet (beta)
For β-pleated sheets what forms are there?
There are parallel, anti parallel or mixed.
How are tertiary structure differ from secondary structures?
Tertiary structures are formed from interactions between two R-groups or between R-groups and peptide backbones. These contracts causes the backtone to bend and fold into its distictive 3-D shape of the SPECIFIC polypeptide
Tertiary structures are made from secondary structures and overall 3-D shape of the SPECIFIC poly peptide
What are the 5 imporant types of R-group interactions and describe them
Hydrogen bonds - IFs between two uncharged polar amino acids or between a charged and polar amino acid
Hydrophobic interaction - Non-polar groups pushed together due to strong repulsion away from H2O
Van der Waals interactions- Temporary charges that attract atoms together for a period of time. (London Dispersion Effect)
Covalent disulfide bonds - Covalent bond between sulfur atoms
Ionic bonds- Happens between a basic and acidic amino acids. (Positive charge attracts negative charge). Creating an Ionic bond
Quaternary structures result when two or more “BLANK” chains form one macromolecule
“Poplypeptides”
Do all proteins exhibit quaternary structure?
No, only if the protein has two or more polypeptide chains.
If they only have one polypeptide chain and are fully functional proteins, they only have a tertiary structure.
What are polypeptide chains called in teritary and quaternary structures?
Thse polypeptide chains are called subunits
Is protein folding spontaneous and if so, why?
Yes, it is spontaneous, due to hydrogen bonding and van der Waals interactions. As well as the folded molecule is more energetically stable than unfolded molecules.
What helps proteins fold correctly in cells?
Molecular chaperones
What is Protein denaturation
Protein denaturation is when a protein unravels and loses it’s shape (Secondary, Teritary or Quaternary)
What is broken in denaturation, what is not broken is denaturation
Intermolecular bonds (that are formed) are broken in Secondary, Teritary or Quaternary strucutre
Peptide bonds between amino acids are not broken (Primary structure is not affected)
What shape do inactive proteins have and why?
They have a disordered shape. They can found into an ordered active conformation when the active protein is needed. Some proteins are regulated by controlling when or where they are folded into active shapes.
Is a denatured protein active?
No, it is biologically inactive
What is a substrate
Substrates are the reactants in an enzyme-catalyzed reaction
What is an active site
An active site is the location on an enzyme where substracte bind and reacts
What are catalysts, and what are enzymes
Catalysts are substances that increase the rate or speed of a reaction, by decreasing the activation energy needed.
An enzyme is a protein that functions as a catalysts
