BIOL 411 Lecture Notes - Lecture 9: Alpha Helix, Protein Folding, Carboxylic Acid

25 views2 pages

champagneeel772

11 Jan 2017

School

Department

Course

Professor

For unlimited access to Class Notes, a Class+ subscription is required.

EXAM 2

Bio411.01

2/22/16

• Proteins: polymers of amino acids joined by peptide bonds

o Also called a polypeptide

o When forming a peptide bond, you lose a water molecule

• An amino acid has a central (alpha) carbon with 4 covalent bonds to an amino group, a

carboxyl group, a hydrogen and an R group

• seuee of aio aids ditates potei foldig hih deteies futio

o primary structure: amino acid sequence

o secondary structure: local segment (the 3D shape of a region of the protein)

▪ 2 different types of regions/ secondary structure possibilities: alpha helix

or beta-(pleated)sheet (some regions are neither)

▪ involves backbone interactions, but the r groups dictate whether a

secondary structure forms

• A region will form if there are no r groups in that region that

prevent it

▪ Hydrogen bond forms between O of carboxyl group of one amino acid

and the H of the amino group of another amino acid further down the

amino acid chain, which brings them together, developing a shape (these

are the backbone interactions- no r groups involved)

o tertiary structure: overall 3-D structure/shape

▪ R-goup iteatios oalet ad eak

▪ Hydrophobic effect is very important

• Some amino acids are hydrophobic and fold down in order to

escape water

• These amino acids are locked in by covalent bonds that form

along the chains that are brought together

o quaternary structure: association of more than one polypeptide coming

together- more than one protein (protein usually refers to the end product- can

have more than one polypeptide)

• Genetic code:

o Triplet code(gn): 3 nucleotides constitute a condon

▪ G= degeneracy (# of possibilities at each position, 4 nucleotide bases)

▪ N= number of positions

• 43= 64 possibilities

▪ The triplet code determines which amino acid is placed in during

translation

• Shown on the amino acid chart

o Start codon is AUG- for all organisms

▪ Starts translation

find more resources at oneclass.com

Unlock document

This preview shows half of the first page of the document.
Unlock all 2 pages and 3 million more documents.

Already have an account? Log in

Related Questions

The sequence of amino acids is considered to be the ________ structure of a protein.

Select one:

a. secondary

b. tertiary

c. quaternary

d. primary

The pattern the backbone folds, for example alpha-helix or beta pleated sheet, is the ________ structure of a protein.

Select one:

a. quaternary

b. secondary

c. tertiary

d. primary

Which type of forces stabilizes the primary structure of a protein?

Select one:

a. Salt bridges

b. Hydrogen bonding between the carbonyl group and amino group

c. Dipole-dipole

d. Peptide bonds

The interaction of the side chains on the amino acids, for example hydrophobic attractions, is the ________ structure of a protein.

Select one:

a. quaternary

b. secondary

c. tertiary

d. primary

violetyellowjacket662

1. A sequence of amino acids in a certain protein is found to be â Ser â Gly â Pro â Gly â

The sequence is most probably part of a(n):

a. beta turn

b. antiparallel beta sheet

c. alpha-helix

d. parallel beta-sheet

e. alapha-sheet

2. Which statement about peptides bonds is NOT TRUE?

There is perfectly free rotation about the peptide bond.

The peptide bond has partial double-bond character.

The peptide bond is shorter than a normal carbon-nitrogen single bond.

The peptide bond usually has a trans configuration with respect to the alpha-carbons of the two amino acids involved in the peptide bond.

Peptide bonds are made via condensation of an amine and a carboxylic acid with loss of water.

3. Which of the following statements about proteins is FALSE?

	Active proteins are generally very loosely structured.
	In water-soluble proteins, hydrophobic amino acid residues are generally buried and not exposed to water.
	Primary structure determines tertiary structure.
	Secondary structure is regular, recurring arrangements in space of nearby amino acid residues in a polypeptide.
	Quaternary structure involves the interaction of subunits in a protein with more than one polypeptide chain.

maroonwallaby335

Protein Structure

a.Different function of proteins and examples:

b. Protein building blocks:

1. atomic composition of building block:

2. "parts" or "functional groups" of the building block:

c. Importance of side chain (R group):

d. Hydrophobic amino acids characteristics:

e. Hydrophilic amino acids characteristics:

f. Charged amino acids characteristics

Copy and complete the table below regarding the characteristics and which groups in the polypeptide interact together at each structural level of the protein.

	characteristics	groups interacting
Primary structure
Secondary structure
Tertiary structure
Quartenary structure

Value: 2

Choose the correct statement(s). You may choose more than one answer.

[mark all correct answers]
a. Proteins are the building blocks of amino acids.

b. Enzymes are a type of protein.

c. Quartenary structure consists of two or more polypeptide chains interacting.

d. Amino acids are made of carbon, hydrogen, nitrogen and phosphorus.

e. The primary structure of a protein is formed due to the interaction of side groups.

Value: 3

Put the following statements regarding the structural levels of a protein formation in the correct order.

Below is a sequence of events. Place them in the order they should occur, number 1 being the first item. Select the step number from the drop down next to each item.

Items to order:

1. Individual amino acids are bonded together via peptide bonds.

2. Two or more polypeptide chains interact via bonds.

3. Hydrogen bonds form between neighboring amino acids within a polypeptide chain allowing the chain to coil or form pleated sheets.

4. Side groups (R) of the individual amino acids interact with each other allowing the protein to assume its three dimensional shape.

Value:4

Put the following statements regarding the structural levels of a protein formation in the correct order

Individual amino acids are bonded together via peptide bonds.	1 2 3 4
Two or more polypeptide chains interact via bonds.	1 2 3 4
Hydrogen bonds form between neighboring amino acids within a polypeptide chain allowing the chain to coil or form pleated sheets.	1 2 3 4
Side groups (R) of the individual amino acids interact with each other allowing the protein to assume its three dimensional shape.	1 2 3 4

Value: 5

Hydrophobic amino acids will be found _______________.

a. In the interior (inner core) of a protein, away from the watery environment.

b. in the interior of a plasma membrane.

c. Both A and B

d. Neither

Value: 6

A protein's function is defined by ____________.

a. enzymatic reactions

b. it's shape.

c. chain of nucleotides.

d. the presence of carbon and hydrogen.

Value: 7

Which of the following is NOT considered a protein function?

a. transport of substances across membrane

b. enzymatic reactions

c. provides structural support

d. carries genetic information

BIOL 411 Lecture Notes - Lecture 9: Alpha Helix, Protein Folding, Carboxylic Acid

Get access

Related Documents

BIOL 411 Lecture Notes - Lecture 10: Alpha Helix, Protein Folding, Transfer Rna

BIOL 411 Lecture Notes - Lecture 4: Carboxylic Acid, Amine, Phosphodiester Bond

[BIOL 411] - Midterm Exam Guide - Ultimate 31 pages long Study Guide!

Related Questions