Unit 2 Test

Question 1

Biomolecules

Answer 1

The main carbon-based molecules found in living organisms there are four main classes: Lipids, proteins, nucleic acids, carbohydrates.Elements commonly included in these biomolecules are: (SPONCH)
sulfur (S)
phosphorus (P)
oxygen (O)
nitrogen (N)
carbon (C)
hydrogen (H)

Question 2

What are organic compounds?

Answer 2

Carbon bonded with hydrogen. (and many have other elements too)

Question 3

Polymers

Answer 3

Considered Polymers: many similar or identical building blocks (monomers) linked by covalent bonds.
Three of the four classes of biomolecules (nucleic acids, proteins and carbohydrates). are considered polymers

Question 4

Monomers

Answer 4

Smallest biomolecule – the building block

Question 5

Hydrolysis

Answer 5

Separating monomers in a polymer by adding water.

Question 6

Dehydration synthesis

Answer 6

Liking two monomers together, creating a polymer. Byproduct is water

Question 6

Elements in carbs

Answer 6

C, H, O; with a ratio of 2:1 (H:O)

Question 7

Carbohydrates

Answer 7

are sugars and starches that serve as fuel and main carbon source.

Question 8

Functional group in carbs

Answer 8

Hydroxyl, carbonyl (adlehyde or ketone).

Question 9

Monomers of carbs/ Function

Answer 9

(CH2O)n
Simplest carbohydrate (monomers)
For example, glucose has the formula C6H12O6.
Most names for sugars end in –ose.
Used for energy

Question 9

IMFs/Bonds present in carbs

Answer 9

Hydrogen bonds, glycosidic linkage (covalent bond).

Question 10

Disaccharides

Answer 10

Two monosaccharides can join to form via dehydration synthesis.

Question 10

Monomer structure

Answer 10

Straight chain vs ring structure.

Question 11

Polysaccharides

Answer 11

polymer of monosaccharides (>100 thousand!)
Most monomers are joined by 1-4 linkages between the glucose molecules.
Plant starches: Amylose, Amylopectin & Cellulose

Question 12

Cellulose

Answer 12

polymer of glucose molecules
major component of the tough cell wall of plant cells.
In a human, the enzymes that digest starch cannot
hydrolyze the bonds in cellulose.
Cellulose in our food passes through the digestive tract
and is eliminated in feces as “insoluble fiber”.

Question 13

Animal Polysaccharide

Answer 13

Animals store glucose in a polysaccharide called glycogen.
Humans and other vertebrates store glycogen in the liver and muscles but only have about a one day supply.

Question 14

Lipids Elements/ functional groups

Answer 14

Phosphate group. C, H, O
oxygen:hydrogen ratio is much greater than in water. (long hydrogen/carbon chains with many less oxygen atoms than in carbohydrates)

Question 15

Types & Functions of lipids

Answer 15

Fats & Oils – energy storage (9Kcal/g) (one gram of fat stores over twice as much energy as carbohydrates per gram)
Phospholipids- cell structures (cell membrane)
Steroids – hormones (cell signaling/ messengers), cholesterol (structure)
Waxes – water loss prevention/protection feathers, fruit, leaves, fur, ears

Question 15

Polarity of Lipids

Answer 15

Non-polar and thus: Hydrophobic

Question 16

Building Blocks of lipids

Answer 16

Glycerol and a fatty acid.

Question 17

Phospholipids

Answer 17

Major component of ALL cell membranes.
Glycerol backbone with 2 fatty acids and a phosphate group.
The phosphate head
is Hydrophilic
Fatty acid tails
are hydrophobic

Question 18

Phospholipid structure

Answer 18

Bilayer sheet, hydrophilic head face outward, hydrophobic tail faces inward.

Question 19

Protein structure/ function

Answer 19

Proteins help control and regulate just about everything living things do.The shape (conformation) determines the function of the specific protein. (function depends on it’s ability to recognize and bind to another molecule or determines the structure (ex/hair)

Question 20

Functions of proteins

Answer 20

Enzymes speed up chemical reactions (ex. pepsin)
Structural proteins provide associations between body parts. (ex. collagen, keratin)
Contractile proteins are found within muscle. (ex. actin)
Defensive proteins include antibodies of the immune system. (ex. IgG)
Signal proteins are best exemplified by hormones and other chemical messengers. (insulin, serotonin)
Receptor proteins transmit signals into cells. (acetylcholine receptor)
Transport proteins carry oxygen. (hemoglobin)
Storage proteins serve as a source of amino acids for developing embryos. (Ferritin)
Regulatory proteins control gene expression (transcription factors)

Question 21

Monomers of proteins

Answer 21

Amino acids consist of four components: a hydrogen atom, a carboxyl group, an amino group, and a variable R group Differences in R groups produce the 20 different amino acids.

Question 22

Elements of proteins

Answer 22

C, H, O, N (S)

Question 23

Polymers of proteins

Answer 23

Dehydration Synthesis joins Amino Acids Remove hydroxyl group from the carboxyl group of one a.a. and the H from the amino group of the adjacent a.a. The resulting covalent bond is called a peptide bond. Many amino acids join to form a string of amino acids called a polypeptide.

Question 24

Bonds in proteins

Answer 24

Peptide bond (c)

Question 25

Determiner of a proteins function

Answer 25

A protein’s function depends on its specific conformation.A functional protein consists of one or more polypeptides that have been precisely twisted, folded, and coiled into a unique shape. It is the order of amino acids that determines what the three-dimensional conformation will be. (think about the types of R groups!)

Question 26

Primary structure

Answer 26

A sequence of amino acids (polypeptides). Amino end, carboxyl end.

Question 27

Secondary structure

Answer 27

Results from hydrogen bonds, in the alpha helix or beta pleated shape

Question 28

Tertiary structure

Answer 28

Interactions between R groups. H-bonds, van der Waals interactions, ionic bond, polypeptide backbone, disulfide bridge.

Question 29

Quaternary structure

Answer 29

Two or more polypeptide subunits

Question 30

Nucleic Acids

Answer 30

DNA, RNA. Function: store + express genetic information. A segment of DNA that codes for a polypeptide is called a gene. DNA (and their genes) is passed by the mechanisms of inheritance. Organisms inherit DNA from their parents in the form of chromosomes.

Question 31

Benedict's Test

Answer 31

A reducing sugar test (sugars(carbs)). Positive result is indicated by a change in color from blue to red or orange, negative green.

Question 31

Shape of RNA +DNA

Answer 31

Helix of sugar phosphate, DNA double helix.

Question 31

Polymers of Nucleic Acids/ How they are formed

Answer 31

phosphodiester bond: -Joins nucleotides together -connects the sugars of one nucleotide to the phosphate group of the next -forms by….you guessed it….dehydration synthesis. Nucleotides stack to form polynucleotides and build polymers of RNA +DNA.

Question 31

Monomers of nucleic acids

Answer 31

Elements: C, H, O, N, P Nucleic acids are polymers. Contain a nitrogenous base, a pentose sugar, and a phosphate group.

Question 31

The central dogma

Answer 31

The flow of genetic information is from DNA -> RNA -> polypeptide.

Question 32

Bonds in nucleic acids

Answer 32

H-bonds, peptide bonds (C).

Question 33

Biuret test

Answer 33

Tests for proteins. A color change from blue to violet is positive.

Question 33

Iodine Test

Answer 33

Test for starches (carbs) a positive test gives a blue black color. Yellow or brown is negative.

Question 34

Brown paper bag test

Answer 34

For lipids- positive is transparent or wet.