CHAPTER 3

Question 1

What four properties of carbon makes it important for life on earth?

Answer 1

-Carbon can form four strong covalent bonds
-Form long chains and ring structures
-Carbon is very abundant in the universe
-Can store large amounts of energy in hydrocarbon chains
-Important because it fuels your body

Question 2

What form does carbon take in our atmosphere?

Answer 2

Carbon takes form as a gas known as carbon dioxide

Question 3

What organisms can use carbon to make sugar?

Answer 3

Plants use carbon dioxide ( as well as sunlight & water) to make glucose (through photosynthesis) C6H12O6

Question 4

Define dehydration reaction

Answer 4

its when you lose one molecule of water to bring something together (EX: bind monomers)

Question 5

Define hydrolysis reaction

Answer 5

you add one molecule of water to break apart something (EX: break a polymer)

Question 6

What are the four types of macromolecules?

Answer 6

-Carbs
-Lipids
-Protein
-Nucleic acids

Question 7

Describe carbs.

Answer 7

Carbohydrates
-molecules consisting of a simple sugars called a monosaccharide
-two monosaccharides makes a disaccharide
-a chain of monosaccharides makes a polysaccharide
-C6H12O6

Question 8

Describe lipids.

Answer 8

Lipids
-compound consisting mainly of carbon & hydrogen atoms linked together forming a non polar covalent bond
-hydrophobic since it is non polar
-fats, waxes, phospholipids, & steroids

Question 9

Describe proteins.

Answer 9

Proteins
-biological polymer constructed from hundreds to thousands of amino acids monomers
-Proteins perform many functions within living cells, including providing structure, transport, and acting as enzymes.

Question 10

Describe nucleic acids.

Answer 10

Nucleic acids
-polymer consisting of many nucleotide monomers
-serves as a blueprint for proteins and, through the actions of proteins, for all cellular structures & activities
-two types -> DNA & RNA

Question 11

How are macromolecules formed?

Answer 11

monomer + monomer + monomer -> polymer

-they are added together through a dehydration reaction which is when you lose a water molecules

Question 12

How is glucose important for cells?

Answer 12

C6H12O6
-the main fuel for molecules for cellular work
-your cells break down glucose molecules and extract their stored energy, giving off carbon dioxide as “exhaust”
-provides immediate energy source to tissues in need of repair
-cells also use the carbon skeleton of glucose as raw material for making other kinds of organic molecules

Question 13

Define isomers.

Answer 13

one of two or more molecules with the same molecular formula but different structures & different properties

Question 14

What are the three types of polysaccharides? Why are they important in living systems? (state function & storage of each)

Answer 14

-all polar due to OH- group; therefore hydrophilic
Starch -> made by plants, stored all over the plant, function is energy storage for plants; excess glucose gets stored away as starch for later use.
Glycogen -> made by animals in the liver, store in liver & muscles, function is energy store for animals; excess glucose gets stored as glycogen for later use
Cellulose -> made by plants, store in plant cell walls & in wood, function is structural support; cannot be broken down by animals but the fiber helps keep digestive system healthy

Question 15

Describe the structure of a fat molecule.

Answer 15

one fat molecule -> made up of 1 glycerol and 3 fatty acids (triglycerides)
lipids -> fats, oils, waves, & steroids (sex hormones)
-fat packs 2x more energy than starch or proteins but takes 2x more energy to burn

Question 16

Define hydrophobic.

Answer 16

Lipids are hydrophobic -> which means they don’t dissolve in water this because they are non polar and water is polar

Question 17

Define saturated fats. Why are they bad? Give examples.

Answer 17

saturated fats -> they have a maximum number of hydrogen atoms attached to them & because of this they form very straight chains & can pack together very tightly; so they are solid at rom temperature

they are bad -> because they can build up as plaque in your blood vessels & arteries, which makes less room for blood to flow through restricting blood flow and increasing your risk of heart attack

examples -> most animal fats like butter; but not fats from fish

Question 18

Define unsaturated fats. Give examples.

Answer 18

unsaturated fats -> less than the maximum number of hydrogen atoms which means you get some carbon double bonds because of this they form bent chains; since they cannot pack together tightly they are liquid at room temperature

examples -> in most plant fat -> olive oil, corn oil, etc; exception -> coconut oil

Question 19

What are phospholipids? How are they important? Diagram it.

Answer 19

-a molecule that is apart of the inner bilayer of biological membranes, having a hydrophilic head and a hydrophobic tail
-important -> because all cells in your body are made of them; it forms the plasma membrane; which surrounds all cells and is selectively permeable which means it lets somethings pass through but not other things “gate keepers”

Question 20

List the major types of proteins & give examples.

Answer 20

-Structural proteins -> provide support ( EX: hair, nails, & animal horns)
-Storage proteins -> provides amino acids for growth (EX: seeds, nuts, egg whites)
-Contractile proteins -> help movement (EX: in muscles)
-Transport proteins -> help transport substances (EX: in hemoglobin in RBC)
-Enzymes -> help chemical reactions by speeding things up (EX: cleaning products & stain removers)

Question 21

What are the structures of proteins?

Answer 21

-primary
-secondary
-tertiary
-quaternary

Question 22

Define primary.

Answer 22

-just the amino acid sequence forming a polypeptide chain
-if you change one amino acid you will change the protein function and it can do its job anymore EX: sickle cell disease

Question 23

Define secondary.

Answer 23

-polypeptide chains forming either an alpha helix (coiled) or a beta pleated sheet (pleated)

-alpha helix found in heart
-beta pleated found in spider webs

Question 24

Define tertiary.

Answer 24

-polypeptides fold, forming specific 3D shapes

Question 25

Define quaternary.

Answer 25

-two or more polypeptides assembled to form larger protein molecules (a subunit)

Question 26

How are amino acids linked together?

Answer 26

-they are joined together by a special type of covalent bond known as peptide bonds, which means you connect carbon to a nitrogen (forming polypeptide chains) the chains fold and form a protein

Question 27

How are proteins “denatured”?

Answer 27

-if a protein is heated, secondary & tertiary structures break down; the protein is neutered
-or extreme pH change of the environment can also cause this
-proteins unravel and cannot function
-which is why high fevers are bad for you

Question 28

What are the structure of nucleic acids?

Answer 28

DNA double helix
-bases: adenine (A), thymine (T), cytosine (C) and guanine (G).
-A always pairs with T
-G always pairs with C

RNA
-4 bases Adenine( A), Cytosine (C) , guanine (G), and uracil (U)
-A always pairs with U
-G always pairs with C

Question 29

What are the three parts of a nucleotide?

Answer 29

-nucleotide is a monomer
-five carbon sugar, phosphate group (negative charge) (these two form the backbone of the DNA molecule), they are link by covalent bonds (strong), last part is called the nitrogenous base (nitrogen in it) they vary and hang off the back bone

Question 30

What are the major differences between DNA & RNA?

Answer 30

DNA(double helix)
-Sugar is called a deoxyribose sugar (which means that there is one less oxygen atom in it; which makes it a rigid molecules which is good because its strong)
-has thymine
-They are held together by hydrogen bonds (weak bonds to make it easy for the two bands to unzip so DNA can copy itself)

RNA(single stranded)
-It has a ribose sugar so it had one more oxygen atom and because of that it is a flexible molecule, which is good bc it has to be able to leave the nucleus and go to the cell
-has uracil

Question 31

what the processes of building protein?

Answer 31

-DNA can replicate itself
-DNA —-Transcription–> mRNA—-Translation—> proteins
/polypeptides