Biological Molecules Unit 1

Question 1

In a Eukaryotic Cell where would you find DNA & RNA? (6)

Answer 1

Nucleus, Cytosol, Mitochondrion, Chloroplast, Lysosome, Plant vacuole

Question 2

What linked patterns make up large molecules?

Answer 2

Polymers, and Monomers

Question 3

What causes polymers to form and break up?

Answer 3

Polymers form via dehydration reactions (loss of water molecule), and are broken up by hydrolysis reactions (gain water molecule)

Question 4

What is the general formula for carbohydrates?

Answer 4

(CH2O)n

Question 5

What is a monosaccharide, and how many carbon atoms does it have?

Answer 5

The most basic form of carbohydrate, and between 3-7 carbon atoms

Question 6

What is a disaccharide and what links it together?

Answer 6

A disaccharide is two monosaccharides attached with a glycosidic linkage

Question 7

How are glycosidic linkages formed?

Answer 7

Dehydration reaction

Question 8

What is a glycosidic linkage?

Answer 8

A type of covalent bond that joins carbohydrate molecules to another group

Question 9

What polysaccharides make up starch and what organisms utilise starch as their main storage?

Answer 9

Amylose and amylopectin (polymers of glucose), and plants and some algae

Question 10

What is the main storage polysaccharide for animals, and what is it similar to?

Answer 10

Glycogen, and similar to amylopectin (glucose polymer in plants/algae)

Question 11

What are the enzymes that hydrolyse starch and glycogen in animals?

Answer 11

Amylases

Question 12

What is the principal structural polysaccharide in plant cell walls?

Answer 12

Cellulose

Question 13

In plants, what are the enzymes that hydrolyse cellulose called?

Answer 13

Cellulases

Question 14

What are the five(5) main functions of carbohydrates?

Answer 14

Storage of energy & materials, transport of energy and materials, energy generation, building material (especially in cells walls of plants/protists, and cell surface activities including recognition and signalling

Question 15

What are lipids, and what are they made of, and are they water soluble?

Answer 15

Lipids are fats, mainly consisting of hydrocarbons (C-C, C-H bonds), they aren’t water soluble

Question 16

What two parts make up fatty acids?

Answer 16

A hydrophilic (water loving) carboxyl group, and an unbranched hydrophobic (water fearing) hydrocarbon chain

Question 17

What makes fatty acids amphipathic?

Answer 17

It’s b/c they have both a hydrophobic, and hydrophilic region

Question 18

What are four(4) structural variations in fatty acids?

Answer 18

Length of carbon chain, saturated (no C-C double bonds) or unsaturated (1 or more C-C double bonds), location of the double bonds, and cis & trans configuration at double bonds and its almost alway cis (introduces bend)

Question 19

What is a triacylglycerol?

Answer 19

They’re fatty acid esters of glycerol (3 carbon chain)

Question 20

Triacylglycerol room temperature state in animals and plants?

Answer 20

Animals- solid at room temperature, make up most of common fat
Plants- liquid at room temperature (oil)

Question 21

What are phospholipids, and describe their structure.

Answer 21

A type of lipid that spontaneously forms a bilayer once placed in a aqueous solution, and has a hydrophilic head, and two hydrophobic tails

Question 22

What are steroid and what is their function?

Answer 22

Steroid are lipids and produce hormones (estrogen & testosterone)

Question 23

What are the six(6) main functions of lipids?

Answer 23

Membrane structure, energy storage, energy generation, thermal insulation, signalling and buoyancy

Question 24

What are proteins?

Answer 24

Polymers composed of many amino acid monomers

Question 25

What are amino acids?

Answer 25

Small molecules that are the building blocks of proteins. Chemically it is a carboxylic acid and an amine group attached to a alpha carbon. See amino acid picture.

Question 26

How are amino acids attached together? And what do they form?

Answer 26

Amino acids are attached via a dehydration reaction, and form an unbranched polypeptide by forming peptide bonds w/ the amino acid residue

Question 27

What is a polypeptide, and what do they create?

Answer 27

Polypeptide is a polymer composed of many amino acid residues, and they form proteins.

Question 28

What are three(3) key features of a polypeptide?

Answer 28

A monotonous repeating N-C-C-N-C-C-N backbone, R groups extending from the backbone w/ differing orders from one polypeptide to another, and N-terminus (amino) and C-terminus (carboxyl) giving the polypeptide polarity.

Question 29

What are the four(4) levels of polypeptide structure?

Answer 29

Primary, secondary, tertiary, and quaternary

Question 30

How many tripeptides are possible?

Answer 30

20^3=8000, b/c there is 20 amino acid groups

Question 31

What are the four(4) main groups of biological molecules?

Answer 31

Lipids (fats & oils), Proteins (amino acids), Carbohydrates (sugars), and nucleic acids (DNA/RNA)

Question 32

What are the three(3) most common carbohydrates?

Answer 32

Glucose, fructose (plant sugar), and sucrose (glucose + fructose)

Question 33

What are the four(4) major examples of polysaccharides in organisms?

Answer 33

Starch, glycogen, cellulose, chitin

Question 34

What is the difference between alpha and beta glucose?

Answer 34

Positioning of 1 of the 4 hydroxyl groups. Alpha is when the -OH is below the carbon ring, and beta is when the -OH is above the carbon ring

Question 35

What is the primary structure of polypeptides/proteins?

Answer 35

The one-dimensional sequence of amino acid residues

Question 36

What is the secondary structure of polypeptides/proteins?

Answer 36

The three-dimensional shape resulting from the hydrogen bonding regions of the backbone that are close by in terms of the primary structure

Question 37

What two(2) shapes do the secondary structure polypeptides/proteins have?

Answer 37

Alpha helix, and beta pleated sheet

Question 38

What is the tertiary structure of the polypeptides/proteins?

Answer 38

The folded shape of the polypeptide arising from interactions among the R groups

Question 39

What is the quaternary structure of the polypeptides/proteins?

Answer 39

Assembly of two or more polypeptide chains into a functional complex, due again to interactions among the R groups.

Question 40

Do all functional proteins have quaternary structure?

Answer 40

No

Question 41

What are the nine(9) functions of proteins?

Answer 41

Catalysis of biochemical reactions by enzymes, Cytoskeleton & motility, Structural proteins, signalling molecules (insulin), transcription factors, cell surface receptors (chemical stimuli), defence (antibodies), storage (starch amino acids), Transport (hemoglobin movement)

Question 42

What are the two(2) types of nucleic acids, and describe them?

Answer 42

DNA-a double stranded helix held together mainly by complementary base pairing btwn strands RNA-a single stranded, but can have some regions double helical structure resulting from intrastrand complementary base pairing

Question 43

What are the five(5) main components of DNA & RNA?

Answer 43

Base (rings containing C & N), sugar (ribose in RNA & deoxyribose in DNA), phosphate group (negative charge), nucleoside (base+sugar), nucleotide (base+sugar+phosphate groups)

Question 44

What are the four(4) main functions of nucleic acids?

Answer 44

Information storage (genes are made of DNA), information retrieval (gene expression), Energy currency (ATP,a ribonucleotide), and catalysis of some biochemical reaction by ribozymes)

Question 45

What are three(3) examples of modified types of molecules?

Answer 45

Glycoproteins, proteoglycans, and glycolipids

Question 46

Two(2) other molecules in cells that do not make up their own class?

Answer 46

Vitamins (small molecules), and secondary metabolites (molecules produced, but are not needed for basic universal processes

Question 47

How are nucleotides linked together?

Answer 47

By phosphodiester bonds to give a polynucleotide strand

Question 48

What is significant about the polynucleotide strand?

Answer 48

It has polarity, the 5' & 3' ends are different

Question 49

Describe the DNA double helix?

Answer 49

Consists of two polynucleotide strands held together firmly by complementary base pairings that run antiparallel to each other.

Question 50

What are the four(4) links named in DNA, and which pair together?

Answer 50

Adenine-Thymine, Cytosine-Guanine

Question 51

What groups does the main structure of proteins consist of? (4)

Answer 51

Central C (alpha carbon), amino group (NH2), carboxyl group (COOH), and a hydrogen atom

Question 52

What exactly happens when a protein becomes 'denatured'?

Answer 52

Protein looses it's higher order structure, but not its primary sequence. They're usually non-functional