chapter 2 learning objectives

Question 1

how many amino acids are there? and how are they all related?

Answer 1

Recall that there are 20 amino acids synthesized by all cells; all amino acids are identical except for the R-group.

Question 2

why are proteins different from each other?

Answer 2

because they are made up of different COMBINATIONS of amino acids.

Question 3

what must polypeptides do in order to become a protein and function properly?

Answer 3

polypeptides must fold into the correct 3D shape in order to become a protein and function properly.

Question 4

what do proteins do?

Answer 4

all the work in the cell
lower energy required to complete a reaction
structure- cell membrane and cytoskeleton

Question 5

what are the 3 parts to a nucleotide?

Answer 5

phosphate, sugar, and nitrogenous base

Question 6

what are examples of steroids?

Answer 6

Cholesterol, estrogen, testosterone, other sex hormones

Question 7

what is the structure of a steroid?

Answer 7

steroids are lipids that have a 4 ring structure.

Question 8

what are fatty acids a part of?

Answer 8

fatty acids are part of triglycerides and part of phospholipids.

Question 9

what kind of lipid are fats and oils?

Answer 9

triglycerides

Question 10

where do fats that are solid at room temperature come from? where do fats the that are oils at room temperature come from?

Answer 10

fats are solid at room temp and come from animals b. oils are liquid at room temp and come from plants

Question 11

Recall the 3 major classes of lipids

Answer 11

triglycerides, steroids, phospholipids.

Question 12

a. Which lipids are used for long-term energy storage? b. Which lipids form the cell membrane? c. Which lipids are a type of hormone?

Answer 12

a. triglycerides
b. phospholipids
c. steroids

Question 13

how are lipids related to each other?

Answer 13

lipids are heterogenous (not as the same as each other) and are not all made up of monomer subunits

Question 14

what are polysaccharides made of?

Answer 14

monosaccarides

Question 15

what are monosaccharides?

Answer 15

monosaccharides are the simplest carbohydrates

Question 16

Explain what it means when a protein is denatured

Answer 16

a protein becomes denatured when there is heat, excessive salt, or the wrong pH. A denatured protein will have its shape changed and function lost.

Question 17

what is a proteins 3d shape is made of?

Answer 17

Primary protein structure, Secondary protein structure, Tertiary protein structure, Quaternary protein structure

Question 18

what is a Primary protein structure, Secondary protein structure, Tertiary protein structure, Quaternary protein structure?

Answer 18

a primary structure is a straight chain,
a secondary structure results from hydrogen bonds between the parts of the polypeptide, it includes coils, sheets, and loops. There are 2 types alpha helix and beta sheet.
A tertiary structure is a secondary structure plus a random additional folds.
A quaternary structure is the 3D shape it is the tertiary subunits joined together.

Question 19

Define ”Protein” “polypeptide” and “amino acid.” Explain the difference between them.

Answer 19

a protein is a macromolecule that is a chain of amino acids. An amino acid is the building block of a protein. A polypeptide is a long chain of amino acids.

Question 20

Define ‘nucleic acid” and “nucleotide.” Explain the difference between them

Answer 20

A nucleic acid is a long polymer if of nucleotides (Examples RNA and DNA). A nucleotide is the building block of nucleic acid.

Question 21

State the function of cholesterol in your cells (regarding the membrane).

Answer 21

Cholesterol regulates and controls membrane transport and also gives the cell its flexibility.

Question 22

Define “saturated” “unsaturated” and “polyunsaturated”

Answer 22

Saturated is single bonds, unsaturated is at least one double bonds and polyunsaturated has a multiple double bonds. Unsaturated and polyunsaturated are liquid at room temperature and saturated fats are solid at room temperature.

Question 23

Explain what a fatty acid is.

Answer 23

A fatty acid is the building block of a lipid. They are usually bonded to a glycerol.

Question 24

Define “lipid” and explain the one property all lipids have in common (hydrophobicity).

Answer 24

a lipid is an organic macromolecule that is made up of fatty acids. They do not dissolve in water because they contain large area dominated by nonpolar carbon-to-carbon hydrogen bonds.

Question 25

Define “carbohydrate.”

Answer 25

a carbohydrate is a macromolecule that contain carbon hydrogen and oxygen.

Question 26

Define “hydrolysis” and “dehydration synthesis.” How are these reactions used to form polymers? How are they used to produce monomers?

Answer 26

hydrolysis is splitting a molecule by adding water, and dehydration synthesis is forming a covalent bond between two molecules by the loss of water. Dehydration synthesis is able to form monomers when enzymes removes an OH (hydroxyl group) from one molecule and a hydrogen atom from another, forming h2o and a new covalent bond between the 2 smaller components; when this is repeated cells can build large polymers consisting of thousands of monomers. Hydrolysis breaks the covalent bonds that link monomers when enzymes use atoms from water to add a OH group to one molecule and a hydrogen atom to another.

Question 27

Define “monomer” and “polymer.”

Answer 27

Monomers are single units of polymers. A polymer is what a long molecule composed of similar subunits, (carbs, protein, and nucleic acids).

Question 28

what is starch?

Answer 28

used by plants to store energy found in storage granules inside plant cells

Question 29

what is glycogen?

Answer 29

used by animals to store energy in the liver.

Question 30

what is cellulose?

Answer 30

a structural polysaccharide found in the cell wall of plants. Cellulose is important for human colon health and is labeled as “fiber” on nutrition labels

Question 31

what is chitin?

Answer 31

a structural polysaccharide found in the cell walls of fungus