7. Describe the structure of the B-cell receptor (BCR). How is the BCR able to trigger a signal transduction pathway when its cytoplasmic tail is only 3 amino acids in length? Outline BCR signal transduction from the point of antigen binding through the NF-κB pathway. What is the result of signal transduction events from the BCR?

1. The following questions concern Jesse Gelsinger who suffered from partial OTC.

            a. In the United States the average person eats far more protein than needed to meet the demands of protein synthesis in their cells. What happens to the extra amino acids? Be specific.

            b. Describe Jesse’s illness.

            c. Briefly describe the experimental treatment he underwent.

Glycophorin A is a glycoprotein that extends across the erythrocyte membrane. The portion of the polypeptide that extends across the membrane bilayer contains 19 amino acid residues that are folded into an alpha -helix.

(a) What is the width of the bilayer that could be spanned by this helix?

(b) How many complete turns of the helix does it take to cross the membrane?

(c) Given that the bilayer interior contains non-polar fatty acyl chains, which of the 20 amino acids would you expect to find among those in the portion of the polypeptide chain that crosses the bilayer?

(d) Would you expect this membrane-spanning helix to be amphipathic? Explain, describing what is meant by the term.

1.The RDA for protein is 0.8 grams/kg of body weight. What would be the recommended amount of protein for a 170 pound male who is 5 feet, 10 inches tall?  Remember: kg body wt= body wt in pounds / 2.2

55 grams

49 grams

62 grams

85 grams

2.Which of the following describes a process in protein synthesis?

The amino acid sequence to make a protein is copied from the DNA by messenger (mRNA).

Protein synthesized in the bloodstream

The function of transfer RNA (tRNA) is to assist in the absorption of amino acids in the diet

The ribosomes leave the nucleus and go into the cytosol of the cell

3’ - TAC AAA GAG GAT CCG ACC TCA ACT - 5”

3. The DNA template for transcription is only one strand of the DNA double helix. How do we know that the mRNA is not based on the sequence of the other DNA strand?

4. What is the anticodon sequence of the tRNA that binds to the fourth codon of this mRNA?

5. Translate the mRNA sequence into the amino acid sequence (use the genetic code table from the lecture slides).

6. How many amino acids does this protein have?

7. Can we tell if this protein was synthesized in a bacterial cell versus eukaryotic cell?

13.

Which of the following are not features commonly observed in α-helices and β-sheets?

14.

1. Fill in the blanks: The α-helices and β-sheets are examples of protein ____________ structure. A protein such as hemoglobin, which is composed of more than one protein ____________, has ____________ structure. A molecule such an enzymatic substrate, a hormone, or a growth factor, is called a ____________.

   	A.	secondary, subunit, quaternary, ligand
   	B.	tertiary, domain, secondary, substrate
   	C.	primary, subunit, secondary, transmitter
   	D.	quaternary, active site, secondary, ligand

17.

1. Find the mismatched pair:

   	A.	ΔG < 0 – Energetically favorable (spontaneous) reaction
   	B.	First Law of Thermodynamics — Energy in a system is not created nor destroyed, only transformed
   	C.	Second Law of Thermodynamics —The entropy of a perfect crystal at 0 K is exactly equal to zero.
   	D.	Entropy (TΔS) – Measurement of disorder in a thermodynamic system

18.

A cell exchanges matter and energy with the environment. From a thermodynamic perspective, a cell is

20.

Which one is not an example of a protein with quaternary structure?

21

1. Chemical reactions carried out by living systems depend upon the ability of some organisms to capture and use matter (atoms, ions, molecules) from non-living sources in the environment. The specific subset of these reactions that break down nutrients in food is called _________, whereas biosynthetic pathways form the subset called _______ and some biochemical pathways that include both types are called _______.

   	A.	catabolism, anabolism, amphibolic
   	B.	catabolism, anabolism, oxidation reactions
   	C.	hydrolysis, reducing reactions, biosynthesis
   	D.	anabolic, amphibolic, anaplerotic

22.

1. Find the mismatched pair function–protein:

   	A.	Insulin – Primary messenger in hormonal signaling
   	B.	Ferritin – Prokaryotic transcription factor
   	C.	Cloned green fluorescent protein – Artificial intracellular marker
   	D.	Rhodopsin – Light receptor

24.

1. Find the incorrect statement:

   	A.	Enzymes may be active inside and outside the cell.
   	B.	Substrate binding and catalysis depend on specific amino acids present in the active site.
   	C.	Enzymes possess certain specific domains called active sites, where catalysis take place.
   	D.	All enzymes are proteins.

In bacteria, the transport of many nutrients, including sugars and amino acids, is driven by the electrochemical H⁺ gradient across the plasma membrane. In E. coli, for example, an H⁺–lactose symporter mediates the active transport of the sugar lactose into the cell. Given what you know about coupled transport, which is likely true of the H⁺–lactose symporter?

Choose one:

A. If the H⁺ gradient were reversed, the transporter could serve as an H⁺–lactose antiport.

B. The transporter oscillates randomly between states in which it is open to either the extracellular space or the cytosol.

C. To undergo the conformational change that releases lactose into the cell, the transporter hydrolyzes ATP.

D. Lactose and H⁺ ions bind to two different conformations of the transporter.

E. The transporter goes through an intermediate state in which the lactose-binding site is open to both sides of the membrane.

11.Which of the following sequences of amino acids is the most likely to be located on the exterior of a water soluble globular protein?

QUESTION 12

1.     Which pair of amino acid side chains might form a London dispersion force type of van der Waals interaction in a globular protein?

QUESTION 13

1.     The β-hairpin consists of antiparallel β-sheets.

  True

  False

QUESTION 14

1.     The α/β barrel topology found in the protein triose phosphate isomerase consists of

QUESTION 15

1.     Which treatment is least likely to cause a protein to denature?

A gene is composed of DNA and a protein is composed amino acids. Describe the steps involved in converting the information contained in a gene into a protein.

**Please include and define all of the following terms in your description:**

Ribosome, template strand, non-template strand, reading frame, complementary, tRNA, mRNA, start codon, stop codon, transcription factors, 5’ to 3’, translation, transcription, gene promoter, RNA polymerase

1- Fatty acyl CoA synthetase catalyses the 2-step fatty acid activation prior to fatty acid synthesis.

True

False

2- Individuals with defects in ammonia clearance tend to suffer neurological problems due to influx of calcium ions into the brain.

True

False

3-Maple syrup disease is largely cause by a defect in the biosynthesis of branched-chain amino acids such as isoleucine.

True

False

4- Uridylylation of PII stimulates the formation of glutamine from glutamate.

True

False

5- Which of the following enzymes catalyzes a highly regulated step involved in both amino acid synthesis and amino acid degradation?

6- The binding of CO to hemoglobin causes it to remain in what conformational state?