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Biological Chemistry

Endocrine and Nervous System: Neurotransmitters

Why have both an endocrine and a nervous system? Although we have not yet studied the endocrine system, you know enough about it to answer the question. Both systems use chemical messages (hormones or neurotransmitters) and they are often identical molecules. The endocrine system releases hormones into the bloodstream and they a

LDL + VLDL cholesterol discussion for biochemistry students

LDL particles have a higher percent content of cholesterol and cholesterol esters than VLDL particles. Describe the catabolism of the VLDL particles that occurs in the circulation and how this accounts for the increased content of cholesterol in the LDL particles. Describe the mechanism by which peripheral tissues take up and ex

Explanation of Plasma Glucagon for Biochemistry Students

In a prolonged fast, plasma glucagon levels are elevated. Describe how this hormone leads to an activation of fatty acid oxidation and explain why this adaptation leads to a gradual but pronounced raise in plasma ketone bodies.

Drawing Structures and Hydrogen Bonds of Water

1. a. Draw the structure of dihydroxyacetone (show all bonds). b. Draw the structure again (showing all bonds), and this time indicate the H bonding of dihydroxyacetone to water. Remember which atoms form H bonds -- you've seen this "rule" several times. Also, each (uncharged) oxygen atom participates in 2 H bonds -- one for

Cell Biology basic questions

1. Glycolysis occurs in the ________, the Krebs cycle occurs in the ________, and the electron transport chain occurs in the ________ membrane. A) mitochondria; mitochondria; mitochondrial B) cytoplasm; mitochondria; mitochondrial C) mitochondria; cytoplasm; plasma D) cytoplasm; cytoplasm; plasma E) cytoplasm; mitochondria;

Michaelis-Menton Equation and finding Vmax and Km from a graph

See the attached .doc Copied from the document. See attachment for more details A) What is the initial velocity v0 called when the substrate concentration [S] >>>KM ([S] )? Label on graph. B) Simplify the above MM equation using the assumption that [S] >>>KM. From this simplified equation, what is the rate const

Peptide Sequencing by Selective Cleavage

I have a peptide sequence with no prolines, 2 positively charged residues at the c-terminal ends of 2 fragments created by trypsin cleavage, but shows no fragments from carboxypeptidases A or B. I thought if a positively charged residue was the c-terminal end of the primary peptide, then I should have seen fragments from carbox

Isolation and Culturing of Olfactory Sensory Neurons

Original posting as formulated by the Student: I am writing a research proposal in which I am attempted to describe an experimental procedure to isolate olfactory sensory neurons (OSNs) and analyze/compare the amino acid sequences of olfactory receptors expressed by individual OSNs. To do this, I am proposing isolating indivi

Discussion of metabolism questions

1. If your goal is to burn fat, you are better off exercising at lower intensity for longer periods of time, as opposed to short burts of more intense exercise. Looking at Figure 9.27(see attachment) explain why this is true on a cellular level. For number 3 can you check my reasoning here.. 3. In step 6 of citric acid cyc

Which of the following is not correct about lactic acid fermentation?

Which of the following is not correct about lactic acid fermentation? a. it is inefficient compared to aerobic respiration b. it uses glucose as a substrate c. it produces two ATP molecules for every glucose molecule d. Oxygen is the final electron acceptor of this pathway. e. Glycolysis is the only energy yielding s

Electron Transport Chain Problem

Which of the following about electron transport chain is true: a. protons are pumped out of the mitochondria by the complexes of the electron transport chain b. the proton gradient established during electron transport is a form of p otential energy c. the electron transport chain can be found in the mitochondria of aero


Which of the following statements about enzymes if false? a. each enzyme has an optimal temperature b. each enzyme has an optimal pH c. most enzymes are highly specific d. some enzymes require cofactors e. most enzymes are RNA molecules

Examine an overall energy requirement

Pathways that have an overall energy requirement are referred to as: a. catabolic reactions b. anabolic reactions c. energy releasing reactions d. energetically feasible reactions e. reactions that will proceed spontaneously

Catabolic reactions

Catabolic reactions involve the: a. breakdown of large organic molecules to simple building blocks b. breakdown of life sustaining processes within cells c. building up of complex organic molecules from simple building blocks d. anabolic production of complex molecules e. expediture of energy

Which of the following statements about the sodium-potassium pump is true

Which of the following statements about the sodium-potassium pump is true: a. it transports hydrogen ions out of the cell b. it transports 3 sodium ions out of the cell in exchange for 2 potassium ions c. it transports 2 sodium ions out of the cell in excahnge for 2 potassium ions d. it transports 2 sodium ions out of

Determining the Chemical Structure of Fat: Cake Mix Example

A food manufacturer is advertising a new cake mix as fat free. Hydrolysis of of the cake mix yields glucose, fructose, glycerol, and amino acids, molecules with hydrocarbon chains and a carboxyl group at the end. Is the cake mix fat free?

Importance of ATP in living organisms

ATP is important in living organisms because: a. like all other nucleic acids, it stores hereditary information b. like RNA, it acts as a source code for the formation of proteins c. it can transfer some of its energy to other chemicals d. it is an important structural component of cell membranes e. it is easily conv

Lipid properties

Which of the following is NOT true of lipids? a. they store energy b. they function as structural components of cellular membranes c. they function as hormones d. they are nonpolar e. the have many oxygen-containing functional groups

Hydrolysis example

Which of the following illustrates hydrolysis? a. the reaction of two monosaccharides to form a disaccharide b. the reaction of two amino acids to form a dipeptide c. the reaction of a hydrogen atom and a hydroxide ion to form water d. the reaction of a fat to form glycerol and fatty acids e. the formation of ATP fro

Human Inability to Digest Cellulose

Cellulose could provide a widely available and cheap form of glucose, but humans cannot digest it. In your own words describe why cellulose cannot be digested by humans. If you were offered a procedure that allowed you to acquire this ability, would you accept? Why or why not?

Same domains and/or motifs are found in many proteins

The same domains and/or motifs are found in many proteins. In fact, a protein's tertiary structure is more conserved (stays the same or similar over many generations) than its amino acid structure. Why would it be advantageous for tertiary structure rather than amino acid sequence to be more reliably conserved among proteins who

Sketch a generic curve for hemoglobin and myoglobin on a graph

Sketch a generic curve for hemoglobin and myoglobin on a graph of ï' vs. [L]. What does the shape of the hemoglobin curve indicate about the nature of hemoglobin binding? (If you are unable to use a drawing program or don't have access to a scanner to scan in your answers using a hand drawn graph, simply describe the shape o

hydroylsis activity assay

I am conducting an activity assay to assess the Enzymatic Hydrolysis of 4-Nitrophenyl ?-D-Glucopyranoside by ?-D-Glucosidase. I am happy with the assay, however one of the components is bovine serum albumin ( 0.2% solution in phosphate buffer, to which my enzyme solution is added). I initially assumed that the BSA acted as so

Buffer Preparation - pH

Can you help me with the following problem? You and your lab partner are responsible for making the buffer 1 M Tris-HCl pH 7.4. After much time, the closest you can get to pH 7.4 is 6.4. Your partner is trying to convince you that 1 pH unit is close enough. What is (or should be) your response?