Question

wlhs/biology/opnet
lipids are soluble (dissolve) in oil but are insoluble (dont dissolve) in water. when mixed with water, the lipid will float on top to form a separate layer. to test for the presence of lipids in food, the sample is placed on a piece of brown or newspaper, and then the paper is held up to the light. a test that is positive for lipids will have a oily spot that is translucent, or clear, on the paper.

1. what does soluble mean?
2. explain the solubility of lipids.
3. how would you test for lipids, and what is a positive result?

proteins
proteins are organic molecules that form muscles, transport o2 (hemoglobin), and act as hormones and enzymes. most importantly, proteins determine how our bodies look and function. their building block is the amino acid. proteins are made of amino acids combined through a dehydration link called a peptide bond. when groups of amino acids are joined together, a protein is formed.

1. what are 2 of the functions of proteins?

a.__________________________
b.__________________________

1. what is the building block of proteins?
2. what is the name of the bond that joins amino acids?

there are about 20 different kinds of amino acids. these amino acids consist of five separate parts. the first is a central carbon atom. second is a carboxyl group (-cooh). third is an amino group (-nh2). fourth is a hydrogen. the fifth group is a variable r group. the only difference in the 20 kinds of amino acids is the
\ group. some
\ groups are very small, others are large, and even others form chains and rings. the sequence and shapes of the
\ groups control the shape and function of the protein.

1. how many different amino acids are there?
2. what part of the amino acid varies from one amino acid to another?
3. what determines the shape and function of a protein?

nucleic acids
the fourth class of organic molecules is the nucleic acids. this class involves the genetic materials, dna and rna. dna is the blueprint of life because it contains instructions on how to make proteins in the body. each individuals dna is unique, which means that each individual has a unique set of proteins. that is why each of us looks and behaves differently. rna is a copy of dna. because dna cant leave the cells nucleus, and because proteins are constructed outside of the nucleus in the cytoplasm, the rna is necessary to carry the instructions from dna to the cytoplasm where the protein is made.

1. what are the two types of nucleic acids?

a.__________________________ b

1. what is the role of dna?
2. how does the role of rna differ from that of dna?

Explanation:

1. The text states "Lipids are soluble (dissolve) in oil", so soluble means to dissolve.
2. The text says "Lipids are soluble (dissolve) in oil but are insoluble (don't dissolve) in water".
3. The text mentions "To test for the presence of lipids in food, the sample is placed on a piece of brown or newspaper, and then the paper is held up to the light. A test that is positive for lipids will have a oily spot that is translucent, or clear, on the paper".
4. The text states "Proteins are organic molecules that form muscles, transport O2 (hemoglobin), and act as hormones and enzymes", so two functions could be forming muscles and transporting O2.
5. The text says "Their building block is the amino acid".
6. The text mentions "Proteins are made of amino acids combined through a dehydration link called a peptide bond".
7. The text states "There are about 20 different kinds of amino acids".
8. The text says "The only difference in the 20 kinds of amino acids is the 'R' group".
9. The text mentions "The sequence and shapes of the 'R' groups control the shape and function of the protein".
10. The text states "This class involves the genetic materials, DNA and RNA".
11. The text says "DNA is the blueprint of life because it contains instructions on how to make proteins in the body".
12. The text mentions "RNA is a copy of DNA. Because DNA can't leave the cell's nucleus, and because proteins are constructed outside of the nucleus in the cytoplasm, the RNA is necessary to carry the instructions from DNA to the cytoplasm where the protein is made".

Answer:

1. To dissolve.
2. Lipids are soluble in oil but insoluble in water.
3. Place the sample on brown or newspaper and hold up to light. Positive result is an oily, translucent spot.
4. a. Form muscles. b. Transport O2.
5. Amino acid.
6. Peptide bond.
7. About 20.
8. The 'R' group.
9. The sequence and shapes of the 'R' groups.
10. a. DNA. b. RNA.
11. DNA is the blueprint of life as it contains instructions to make proteins.
12. RNA is a copy of DNA and carries instructions from DNA (which can't leave the nucleus) to the cytoplasm for protein - making.