Foods and Nutrition 1021 Chapter Notes - Chapter 6: Blood Sugar, Blood Proteins, Chemical Bond

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redprairie-dog477

25 Sep 2017

School

Western University

Department

Foods and Nutrition

Course

Foods and Nutrition 1021

Professor

Noelle Martin

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Document Summary

One difference between proteins and carbs and fat is that proteins contain nitrogen atoms in addition to carbon, hydrogen and oxygen. These nitrogen atoms give the name amino to the amino acids (nitrogen containing) Amino acids are the building blocks of protein. Amino acids in a strand of protein are all different in contrast to the glucose repeating in carbs: may contain up to 20 different strands. All amino acids have the same chemical backbone consisting of a single carbon atom with both an amine group (the nitrogen containing portion) and an acid group attached to it. Each amino acid also has a distinctive side chain that gives it identity and chemical nature. The body can make about half of the 20 amino acids for itself, given the needed parts: fragments from carbs or other amino acids to form the backbones and nitrogen from other amino acids.

Related Questions

1. Polypeptide strands is the active form of a digestive enzyme in the stomach that breaks polypeptide chains into smaller polypeptides.

2. Cleavage of proteins by pepsin in the stomach results in formation of pepsinogen which get broken down further in the small intestine.

3. An amino acid chain made up of three amino acids joined together is called a tripeptide.

4. Dipeptide describes an amino acid chain made up of two amino acids joined together.

5. The 20 different amino acids are the building blocks used for protein synthesis.

6. Amino acid pools are stockpiles found in the blood and other cells of the body that can be used to build new proteins.

7. The continual process of degrading and synthesizing protein is called protein turnover.

8. The stomach produces pepsin, which denatures protein.

9. Denaturation occurs when a protein is exposed to heat, acid, bases, or mechanical agitation resulting in unfolding of the protein, though the peptide bonds remain intact.

10. The part of an amino acid that contains nitrogen is called the amine group.

11. The acid group is also known as the carboxyl group.

12. Single amino acids that are absorbed in the small intestine travel to the liver via the portal vein.

Please correct these sentences AS SOON AS POSSIBLE.. Some of them are not correct and I didn't figure out what are they!

violetdog828

Proteins are naturally occurring polymers formed by condensation reactions of amino acids, which have the general structure

In this structure, –R represents –H, –CH₃, or another group of atoms; there are 20 different natural amino acids, and each has one of 20 different R groups. (a) Draw the general structure of a protein formed by condensation polymerization of the generic amino acid shown here. (b) When only a few amino acids react to make a chain, the product is called a “peptide” rather than a protein; only when there are 50 amino acids or more in the chain would the molecule be called a protein. For three amino acids (distinguished by having three different R groups, R1, R2, and R3), draw the peptide that results from their condensation reactions. (c) The order in which the R groups exist in a peptide or protein has a huge influence on its biological activity. To distinguish different peptides and proteins, chemists call the first amino acid the one at the “N terminus” and the last one the one at the “C terminus.” From your drawing in part (b) you should be able to figure out what “N terminus” and “C terminus” mean. How many different peptides can be made from your three different amino acids?

purpleyak702

What is the percent sequence identity between hemoglobin (2HHB) and myoglobin (1A6M)?

	A.	93%
	B.	39.46%
	C.	25.17%
	D.	4.08%

QUESTION 2

Which of the following statements is consistent with the sequence similarity parameter?

	A.	The abundance of amino acids with similar properties that are arranged in the same order is equal to the abundance of identical amino acids.
	B.	These parameters are not related and cannot be compared.
	C.	The abundance of amino acids with similar properties that are arranged in the same order is less than the abundance of identical amino acids.
	D.	The abundance of amino acids with similar properties that are arranged in the same order is higher than the abundance of identical amino acids.

QUESTION 3

Which of the following statements is consistent with the similarity parameter and visualization of the aligned structures?

	A.	Hemoglobin and myoglobin do not have similar structures.
	B.	Hemoglobin and myoglobin have only moderately similar structures, as indicated by the large abundance of gray chains.
	C.	Hemoglobin and myoglobin have very similar structures.
	D.	Hemoglobin and myoglobin are perfectly aligned at every amino acid.

QUESTION 4

Hemoglobin (2HHB) is ___ amino acids shorter than myoglobin; the sequence alignment considers only ___ amino acids, and alignment results show that hemoglobin is missing a contiguous strand of ___ amino acids.

	A.	10; 141; 6
	B.	10; 141; 5
	C.	10; 147; 6
	D.	10; 147; 5

QUESTION 5

Which of the following statements best describes the evolutionary relationship between hemoglobin and myoglobin?

	A.	The low sequence identity indicates that hemoglobin and myoglobin are not related, as tertiary structure cannot be used to study protein evolution.
	B.	Both the high sequence identity and structural similarity suggest that hemoglobin and myoglobin are related.
	C.	The difference in sequence identity and similarity values suggests that hemoglobin and myoglobin are related.
	D.	The high structural similarity suggests that hemoglobin and myoglobin are related, while the low sequence identity suggests that the genes for each protein have diverged through mutation and deletion of several amino acids.

QUESTION 6

The comparison of sequences and tertiary structures in this exercise indicates that:

	A.	only similar amino acid sequences can provide the same tertiary structure.
	B.	different amino acid sequences can provide very similar tertiary structures.

QUESTION 7

The structures of deoxyhemoglobin and oxyhemoglobin are derived from the same source, have the same exact amino acid sequence and length, and differ only in the presence of noncovalently bound oxygen.

	A.	True
	B.	False

QUESTION 8

When using the Sequencing and Structure Alignment tool, the degree of the structural similarity is shown by the superimposition of the backbones. Accordingly, which of the following statement best describes the comparison of deoxyhemoglobin and oxyhemoglobin?

	A.	Only slight differences in the backbone traces occur throughout the aligned proteins.
	B.	The only differences in the backbone traces occur near the oxygen-binding sites.
	C.	The backbone traces of the proteins are drastically different.
	D.	The backbone traces of the proteins are identical.

QUESTION 9

The alignment of 2HHB and 1HHO shows that the binding of oxygen results in _______ in the protein.

	A.	minor conformational changes at sites proximal and distal to the oxygen-binding site
	B.	no conformational change
	C.	drastic conformational changes
	D.	minor conformational changes only within the oxygen-binding site

QUESTION 10

The alignment of 2HHB and 1HHO shows that the conformation of the Fe-heme group _____ upon oxygen binding.

	A.	changes
	B.	does not change

Foods and Nutrition 1021 Chapter Notes - Chapter 6: Blood Sugar, Blood Proteins, Chemical Bond

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