Chapter 3, Proteins

Question 1

What are the 5 elements that are found in proteins

Answer 1

Hydrogen,Carbon,Nitrogen,Oxygen,Sulfur

Question 2

What is the general terms for the monomers of proteins

The building blocks of proteins

Answer 2

Amino Acids

Question 3

How many different amino acids are used in human proteins

Answer 3

There are 20 amino acids for the human body

Question 4

What is the general term for polymers of proteins

What is the protein chains called

Answer 4

Polypetides

Question 5

What are the 6 important functions of proteins in the body

Answer 5

Catalysts, Defence, Movement, Signalling,Structure,Transport

Question 6

Describe these 6 protein functions in the human body

Answer 6

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

Question 7

What two functional groups are amino acids made from

Answer 7

Carboxyl (COO-) and Amino (NH2+) functional groups

Question 8

What type of molecules are amino acids

Answer 8

Organic molecules

Question 9

How are amino acids have unique properties compared to each other

Answer 9

They contain different side chains which are knownas R-groups

Question 10

What is an α-carbon

Answer 10

Central carbon that is connected to two functional groups in an amino acid

Question 11

How would you draw an amino acid

Answer 11

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

Question 12

How many types of amino acids are there

Answer 12

4
Uncharged Polar, Nonpolar,
Charged Acidic(-) and Basic (+)

Amino acids can be grouped from the properties of the side chains.

Question 13

How can you tell the difference between the types of amino acids

Answer 13

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

Question 14

What happens to amino acids in water

Answer 14

The functional groups inoize to NH3+ and COO-, allowsing them to stay dissolvedi n solution and the amino acds to be more reactive

Question 15

How do amino acids polymerize

Answer 15

Amino acids polymerize when:
A bond forms between a carboxyl group of one amino acid to another amino group the other amino acid

Question 16

What bond is between the two monomers of amino acids

Answer 16

The bond between the C-N is called a peptide bond

Question 17

What is N-termius and C-terminus of an amino acid

Answer 17

N-termius = Starting the amino acid chain, ALWAYS starts with an AMINO group
C-terminus=Ending the chain, ALWAYS ends with a carboxyl group

Question 18

Why is the flexibility of the amino acid chain important?

Answer 18

The flexibility of the c-c bonds allows the amino acids to fold into 3-D proteins shapes

Question 19

An “Blank” is a polymer of less than 50 amino acids

Answer 19

“Oligopeptide”

Question 20

An “Blank” is a polymer of more than 50 amino acids

Answer 20

“Polypeptide”

Question 21

Proteins can be used to refer to what amino acid chain

Answer 21

To any amino acid chains, but more formally refers to the complete,functional form of the molecule

Question 22

Each protein has a unique linear “blank” of amino acids

Answer 22

“Sequence”

Question 23

Proteins have unparalleled divesity of what?

Answer 23

of size,shape and chemical properties

Question 24

How is the 3-D shape of a protein determined and what does the shape do?

Answer 24

The sequence of amino acids determines a protein’s 3-D structure. It’s structure determines if function

Question 25

# From Q25 What type of structure does this represent

Answer 25

A primary protein structure

Question 26

What is an example of the shape of a protein being important to its function

Answer 26

An enzyme

Question 27

How is the primary structure of a protein determined

Answer 27

By our genetic code (DNA)

Question 28

What is the central dogma

Answer 28

It is our main method of transporting genetic information into usable proteins and components (DNA -> RNA -> Proteins)

Question 29

What strucuture is fundamental for higher levels of protein structure and why?

Answer 29

Primary structures, The amino acid R-groups affect a polypeptide's properties and functions. A single amino acid change can radically alter protein function

Question 30

What is characterisic of proteins

Answer 30

Each has a charcteristic folded shape, which is neccsary for its function and shape is ALWAYS related to function

Question 31

How is a protein's secondary structure formed? And what situation must be satisfed for this secondary structure to form

Answer 31

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

Question 32

What are the two major types of secondary structures

Answer 32

α-helix (Alpha) β-pleated sheet (beta)

Question 33

For β-pleated sheets what forms are there?

Answer 33

There are parallel, anti parallel or mixed.

Question 34

How are tertiary structure differ from secondary structures?

Answer 34

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

Question 35

What are the 5 imporant types of R-group interactions and describe them

Answer 35

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

Question 36

Quaternary structures result when two or more "BLANK" chains form one macromolecule

Answer 36

"Poplypeptides"

Question 37

Do all proteins exhibit quaternary structure?

Answer 37

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.

Question 38

What are polypeptide chains called in teritary and quaternary structures?

Answer 38

Thse polypeptide chains are called subunits

Question 39

Is protein folding spontaneous and if so, why?

Answer 39

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.

Question 40

What helps proteins fold correctly in cells?

Answer 40

Molecular chaperones

Question 41

What is Protein denaturation

Answer 41

Protein denaturation is when a protein unravels and loses it's shape (Secondary, Teritary or Quaternary)

Question 42

What is broken in denaturation, what is not broken is denaturation

Answer 42

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)

Question 43

What shape do inactive proteins have and why?

Answer 43

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.

Question 44

Is a denatured protein active?

Answer 44

No, it is biologically inactive

Question 45

What is a substrate

Answer 45

Substrates are the reactants in an enzyme-catalyzed reaction

Question 46

What is an active site

Answer 46

An active site is the location on an enzyme where substracte bind and reacts

Question 47

What are catalysts, and what are enzymes

Answer 47

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