BSCI-1510 Lecture 3: Kendal Broadie- Protein Structure, Folding, and Function- August 29th, 2018

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burgundyhound116

22 Dec 2018

School

Vanderbilt University

Department

Biological Sciences

Course

BSCI-1510

Professor

Broadie Kendal

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Document Summary

Midterm 1, lecture 4: protein structure, folding, and function. Have an amino n- terminus (left side) and a carboxy c-terminus (right side) # of proteins that can be created is essentially unlimited. 20 aas (amino acids) and 20^n combinations and post translational modifications (aka covalently bonded addition of a group like -oh, acetyl, etc. or other proteins to the amino acid side chains) Primary (i) is linear sequence of amino acids with covalent peptide bonds in between. Secondary (ii) is the folding of the structure via h (hydrogen) bonds between backbone peptide bonds (h bonding occurs between h and o atoms on a protein) 2 types, which one depends of which is the most stable option (affected by. Stabilized by h bonds between n-h (peptide bond) and c=o (bond that is 4 aas away on the polypeptide) R side groups (aka aa side groups) radiate out from the helix.

Related Questions

1. The level of protein structure that is stabilized primarilyby non-covalent interactions between the side chains within asingle polypeptide chain is refered to as its:

A) primary structure

B) secondary structure

C) tertiary structure

D) quaternary structure

E) none of the above

2. Collagen, a strong fibrous protein found in connectivetissue, bone, and the extracellular matrix, has a structure inwhich three left-handed helices wind around each other to form aright-handed triple helix. The primary structure of collagen has arepeat unit of -(Gly-X-Pro)- Which of the following bonds stabilizethe collagen triple helix? (mark all that apply)

A) Hydrogen bonds between hydroxyproline residues

B) Hydrogen bonds between N-H and C=O

C) Ionic bonds between amino acid side chains

D) Hydrogen bonds between charged amino acids

3. The non-covalent forces that stabilize the Beta-strandconformation of peptides include:

A) H-bonds between amide C=O and amide NH

B) Van der Waals packing between the peptide backbone atoms

C) Van der Waals packing due to side chain interdigitation

D) Only A and B above

E) None of the above

4. What is the approximate length difference of a 22-kDasingle-stranded ?-helical protein segment vs. a 22-kDasingle-stranded ?-strand protein segment? Assume a mean residuemass of 110 Da. Show work.

5. Circular dichroism measurements have shown that the peptidebackbone of poly-l-lysine (KKKKKKK) adopts a random coilconformation at pH 7.0, but becomes ?-helical as the pH is raisedabove 10. This observation is known as the

magentaotter572

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

1. You have the following prokaryotic DNA sequence: 5â²-GGACTAGACAATAGGGACCTAGAGATTCCGAAA-3â² 3â²-CCTGATCTGTTATCCCTGGATCTCTAAGGCTTT-5â² If the top strand is the template strand which sequence below is the correct mRNA transcript? A. 5â²-GGACUAGACAAUAGGGACCUAGAGAUUCCGAAAâ3â² B. 5'-UUUCGGAAUCUCUAGGUCCCUAUUGUCUAGUCC-3' C. 5'-CCUGAUCUGUUAUCCCUGGAUCUCUAAGGCUUU-3' D. None of the above are correct

2.Starting in the cytoplasm with a fully mature mRNA explain the process of translation initiation and then elongation and termination to me.

3.Prior to export from the nucleus, pre-mRNA must be processed. What specifically does this entail?

4.The biosynthetic pathway for the two amino acids E and H is shown schematically in the figure. You are able to show experimentally that E inhibits enzyme V, and H inhibits enzyme X. The most logical hypothesis regarding the regulation of Enzyme T would be that it is most likely subject to feedback inhibition by E alone. True or False?

5. A. kinase B. ligase C. polymerase D. oxido-reductase E. Phosphatase F. protease G. nuclease H. ATPase 1. Removes a phosphate group from a molecule 2. Hydrolyzes ATP 3. Hydrolyzes bonds between nucleotides 4. Adds phosphate groups to molecules 5. Catalyzes reactions in which one molecule is oxidized and another is reduced 6. Hydrolyzes peptide bonds 7. Joins two ends of DNA together 8. Catalyzes the synthesis of polymers such as RNA and DNA

6. Looking at the figure showing the change in reaction rate for two different enzymes that both utilize the same substrate, answer the following questions. a. What is the approximate Vmax for enzyme B ? b. What is the approximate Vmax for enzyme A ? c. What is the approximate Km for the enzyme which has a higher affinity for the substrate uM.

7. Answer the following question either yes or no (spell out the word, do not abbreviate as y or n). Looking at the following coupled reaction: Luciferase luciferin + O 2 ==========> oxyluciferin + light âG = + + Mg2+ ATP <=> AMP + PPi âG = - - - a. Based on your knowledge of free energy change and reactions would this coupled reaction occur ? b. Would changing the second step from ATP<=> AMP + PPi âG = - - - to ATP <=> ADP + Pi âG = - change your answer

7.Spontaneous reactions by definition will happen instantaneously. Why false?

8. Each of the following questions apply to the image of the channel protein. The purple sphere is a charged ion. Type your response to each question in the blank provided. a. Based you on what you know about cells and ions, what does the tri-lobed red and white molecule represent (although there aren't anywhere near enough of them shown) ? b. Since the question stated the purple sphere was a charged particle, using what you know about the tri-lobed red and white molecule what is the charge of the purples sphere c. On the extracellular space, on the right side of the purple sphere, there are two tri-lobed red and white molecules in close proximity to one another. The red of one appears to be attracted to the white of the other. What type of bond is this ? d. Based on your knowledge of proteins that interact with the membrane and the properties of the membrane, to what family of amino acids would the amino acid marked by A. most likely belong? ?

BSCI-1510 Lecture 3: Kendal Broadie- Protein Structure, Folding, and Function- August 29th, 2018

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