Question

PLEASE HELP ME
1. Which of the following types of atoms is NOT found in every organic molecule of life which includes carbohydrates, lipids, proteins, and nucleic acids?
A. carbon
B. nitrogen
C. oxygen
D. hydrogen
2. As a scientist, you are tasked to determine which organic molecules are present in a food sample you are given. You find that iodine turns from rust to black and there is no change when using other indicators. Which organic molecule do you conclude is present in the food sample?
A. protein
B. lipid
C. nucleic acid
star

Answer 1

Do you have some guess before we go into details?

Answer 2

i think the first ones c

Answer 3

That is not totally correct but a good guess. Oxygen is found in the most of the macro molecules. The correct answer is actually nitrogen, which is more rarely found in lipids. But even then, nitrogen CAN be found in lipids Lecitin being an example (see attachment)

Answer 4

thank u

Answer 5

do u know the 2nd one

Answer 6

I sure do. The iodine test shows if there is the molecule "amylose" present do you know what kind of molecule amylose is?

Answer 7

(I think it is one of the options you are missing)

Answer 8

no

Answer 9

Sugar/saccharides/carbohydrates is not among the options?

Answer 10

ok

Answer 11

Usually what iodine does is that it coordinates with the molecule amylose by coordinating with the helical structure of amylose in aqueous solutions. I've not experienced iodine being an indication of other macromolecules.

Answer 12

oh ok

Answer 13

so its a

Answer 14

Well no it isn't proteins. What I am saying is it is not A, B or C, not any of the options you have listed. Not from what I've learned or seen.

Answer 15

ok thanks

Answer 16

can u help me with 2 more question i want to make sure they are right

Answer 17

Sure.

Answer 18

Which of the following statements is not true about proteins? (Points : 2)
When proteins become denatured, the bonds between the amino acids break changing the shape of the active site.
Proteins are made up of a series of amino acids hooked together with peptide bonds.
High temperatures, strong acids, and strong bases can cause proteins to become denatured

Answer 19

i think its c

Answer 20

no b sorry

Answer 21

It say which of the following is NOT true. So are you sure it is B?

Answer 22

Proteins primary structure is the amino acid sequence, each amino acid held together by a peptide bond which is not easy to break, so B is not false.
The answer being false is A: When a protein becomes denatured, it loses its structure is, but it isn't the peptide bonds that are broken, instead it is the intermolecular bonds/forces that are broken (e.g. hydrogen bonds, ion bonds, hydrophobic bonds)

Answer 23

thanks last one

Answer 24

Which of the following is a true statement about enzymes? (Points : 2)
Enzymes speed up a chemical reaction by increasing the activation energy.
Enzymes are changed during a chemical reaction.
Strong acids and strong bases increase the effectiveness of enzyme

Answer 25

i think its a

Answer 26

Correct! :)

Answer 27

thank u

Answer 28

No problem at all. I hope the questions makes more sense, if not you can look most of the protein structure up on the Wikipedia. Their articles about protein structure and function are not bad at all.

Answer 29

starch

Answer 30

Ahhh starch is also sugar/saccharides/carbohydrates :) I thought the "star" part in your question was something else, that is why I asked continuously for another answer :)