Thread of Life

Question 0

3 Ethical issues with DNA fingerprinting and testing:

Answer 0

• Who owns and has access to genetic information?
• Should parents have the right to test their children?
• Should tests be performed for genetic diseases?

Question 1

What four steps are uses to form a DNA fingerprint?

Answer 1

1- DNA sample cut into fragments using a restriction enzyme
2- Fragments separated by electrophoresis
3- Fragments marked with a probe and exposed on x ray film
4- black bars are produced which is the fingerprint

Question 2

What is the order of a substance with a constant half life?

Answer 2

1st order

Question 3

What effect does increasing temperature have on k?

Answer 3

The value of k increases

Question 4

What step are particles in the rate equation involved in?

Answer 4

The rate determining step

Question 5

What is the rate determining step?

Answer 5

The slowest step in a multi step reaction

Question 6

In a first order reaction what happens to rate when conc of the reactant is doubled?

Answer 6

It doubles

Question 7

What are optical isomers?

Answer 7

Molecules with a chiral centre that are non- superimposable mirror images

Question 8

What is a racemic mixture?

Answer 8

A mixture with a 50:50 mixture of d and l isomers

Question 9

What two functional groups do amino acids contain?

Answer 9

Carboxyl COOH and Amino NH2

Question 10

What does an amino acid form in a neutral solution?

Answer 10

A zwitterion

Question 11

What happens to an amino acid in an acidic solution?

Answer 11

The amino group is protonated

Question 12

What type of reaction joins forms a polypeptide and what are the bonds between amino acids?

Answer 12

Condensation

peptide

Question 13

What are the four bonds that maintain a protein’s tertiary structure?

Answer 13

ID-ID
hydrogen bonds
Ionic bonds
Covalent bonds

Question 14

What are the conditions and reagents for hydrolysis of proteins?

Answer 14

Mod conc acid/alkali

Reflux

Question 15

How can amino acids be identified?

Answer 15

TLC with ninhydrin locating agent

Question 16

At low concentrations of substrate, what is the order with respect to the substrate and what is the rate equation?

Answer 16

Rate= k[E] [S]

First order

Question 17

At high concentrations of substrate what is the rate equation and order with respect to the substrate?

Answer 17

Rate = k[E]

Zero order

Question 18

Why are enzymes used in industry?

Answer 18

Specific
Work at low temps
Work in aqueous environment
Higher atom economy

Question 19

How are reactive metals extracted?

Answer 19

By electrolysis

Question 20

How are less reactive metals extracted?

Answer 20

By reduction with carbon/CO

Question 21

Examples of barrier protection?

What does it prevent?

Answer 21

Paint, grease, oil, polymer coating

Oxygen/water coming into contact with iron and steel

Question 22

What is sacrificial protection?

Answer 22

attaching a more reactive metal to iron structures, the reactive metal oxidises instead of the protected metal

Question 23

What is a transition metal?

Answer 23

A d block element which forms at least 1 ion with a partially filled d sub shell

Question 24

Which electrons are lost first when a d block element forms ions?

Answer 24

4s

Question 25

What are 3 physical properties of d block elements?

Answer 25

Good conductors of heat and electricity
High tensile strength
High melting/boiling point

Question 26

What are the four important chemical properties of transition metals?

Answer 26

Variable oxidation states
Coloured ions
Complexes
Catalysts

Question 27

What is a ligand?

Answer 27

A molecule or anion with one or more lone pairs of electrons

Question 28

What is the coordination number?

Answer 28

Number of bonds between ligand and central metal atoms