Molecules

Question 1

Describe water in biochemistry

Answer 1

-Excellent solvent capable of dissolving a variety of organic and inorganic substances -Most reactions take place in an aqueous solution -Transport ability -Effect on hydrophillic and hydrophobic molecules

Question 2

What does potassium do?

Answer 2

Acts as a buffer in neurones

Question 3

What does calcium do?

Answer 3

Is the main component in calcium pectate

Question 4

What does magnesium do?

Answer 4

Is a component in chlorophyll that aids photosynthesis

Question 5

What does iron do?

Answer 5

Iron is part of the haem groups in haemoglobin

Question 6

What is hydrogen carbonate?

Answer 6

A natural buffer

Question 7

What does nitrate do?

Answer 7

Nitrate is a component of amino acids/nucleic acids and chlorophyll

Question 8

What does phosphate do?

Answer 8

Phosphate is a major component in phospholipids, ATP, nucleic acids

Question 9

What are monosaccharides?

Answer 9

Monomers of sugar, such as alpha-glucose, beta-glucose and fructose

Question 10

What are dissaccharides?

Answer 10

Two monomers joined together, such as maltose (2 a-glucoses) or sucrose (a-glucose and fructose)

Question 11

What are polysaccharides?

Answer 11

Long chains of many monosaccharides

Question 12

Describe the structure and function of cellulose

Answer 12

-Cellulose plays a structural role in plants, and is found in the cell wall of plants. -Cellulose is a bunch of beta glucose unbranched, alternating chains bonded together. Due to the “flipped nature” of the chains hydrogen bonds between the strands occurs. -Many of these together creates microfibrils. Microfibirls run against each other in a lattice structure to increase tensile strength.

Question 13

Describe the structure and function of starch

Answer 13

-Starch plays a storage role in plants. It is made up of amylose, unbranched chains of alpha glucose, and amylopectin, branched chains of alpha glucose (with 1,6 glycosidic bonds) -Starch is compact, insoluble, and has more terminal ends for faster hydrolysis

Question 14

Describe the structure and function of glycogen

Answer 14

-Plays a storage role in animals. It is long branched chains of alpha-glucose monomers (1,6 glycosidic bonds) -Glycogen is compact, insoluble, and has more terminal ends for faster hydrolysis

Question 15

What are lipids?

Answer 15

Organic molecules, the main two types being phospholipids and triglycerides

Question 16

What are triglycerides?

Answer 16

Condensation products of glycerol and fatty acids

Question 17

What are saturated fats?

Answer 17

Fats containing maximum number of hydrogen atoms, and are linked by C-C single bonds

Question 18

What are unsaturated fats?

Answer 18

Fats linked by C=C double bonds

Question 19

What are phospholipids?

Answer 19

They are an insoluble and polar form of lipid. They are found in the cell membrane, and due to their polarity are important to determining orientation and function of cell membranes

Question 20

What are proteins?

Answer 20

Proteins are condensation products of amino acids

Question 21

What is primary structure?

Answer 21

Sequence of amino acids in a polypeptide chain, joined by peptide bonds

Question 22

What is secondary structure?

Answer 22

Alpha helix, or beta pleated sheets

Question 23

What is tertiary structure?

Answer 23

Folding of polypeptide chain further

Question 24

What is quarternary structure?

Answer 24

More than 1 polypeptide making up a protein

Question 25

Describe the bonds in primary structure

Answer 25

Peptide

Question 26

Describe the bonds in secondary structure

Answer 26

Hydrogen

Question 27

Describe the bonds in tertiary structure

Answer 27

Hydrogen, ionic, disulfide, and hydrophobic interactions

Question 28

Describe the bonds in quarternary structure

Answer 28

Mostly disulfide

Question 29

What is fibrous protein?

Answer 29

-Insoluble proteins made up of polypeptide chains arranged to form fibres, with a structural role -Collagen for example, is in tendons and joins muscle to bone.

Question 30

What is globular protein?

Answer 30

-Proteins with a metabolic role. -They are capable of forming specific 3D shapes for their role -Enzymes, antibodies and haemoglobin are all examples

Question 31

What are conjugated proteins?

Answer 31

Quarternary structures containing prosthetic groups, for example, glycoproteins and haemoglobin

Question 32

What are nucleic acids?

Answer 32

Condensation products of nucleotides. Nucleic acid chains form DNA as two anti-parallel strands

Question 33

Name 5 differences between RNA and DNA

Answer 33

DNA: Deoxyribose, double stranded, Adenine-Thymine, millions of nucleotides long, 1 type RNA: Ribose, single stranded, Adenine-Uracil, hundreds of nucleotides long, 3 primary types

Question 34

Name the 3 primary types of RNA

Answer 34

ribosomal (rRNA): made in nucleolus messenger (mRNA): carries DNA code from nucleus to ribosomes transfer (tRNA): carries amino acids to ribosomes

Question 35

Describe the process of DNA replication

Answer 35

-DNA helicase "unzips" DNA strands by breaking hydrogen bonds -Each original strand acts as the template for the free nucleotides to join onto, following base pair rules. -DNA polymerase creates the free nucleotides, so a new strand is joined together with the old. -This is why it is called semi-conservative replication

Question 36

Describe the iodine test

Answer 36

Tests for starch; yellow-brown to blue black if positive result

Question 37

Describe the Benedict's test

Answer 37

Tests for reducing sugars; blue to brick red precipitate if positive result

Question 38

Describe the clinistix test

Answer 38

Tests for glucose; paper will turn purple/blue if positive result

Question 39

Describe the Biuret test

Answer 39

Tests for protein; blue to lilac/purple if positive result

Question 40

How do you calculate an Rf value?

Answer 40

Distance moved by a solute divided by the distance the solvent has moved forward

Question 41

Draw a triglyceride molecule

Answer 41

Where R represents the hydrocarbon chain

Question 42

Draw a phospholipid molecule

Answer 42

Question 43

Draw the general structure of amino acids

Answer 43