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Flashcards in Thread of Life Deck (29):
0

What four steps are uses to form a DNA fingerprint?

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

1

3 Ethical issues with DNA fingerprinting and testing:

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

2

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

1st order

3

What effect does increasing temperature have on k?

The value of k increases

4

What step are particles in the rate equation involved in?

The rate determining step

5

What is the rate determining step?

The slowest step in a multi step reaction

6

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

It doubles

7

What are optical isomers?

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

8

What is a racemic mixture?

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

9

What two functional groups do amino acids contain?

Carboxyl COOH and Amino NH2

10

What does an amino acid form in a neutral solution?

A zwitterion

11

What happens to an amino acid in an acidic solution?

The amino group is protonated

12

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

Condensation
peptide

13

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

ID-ID
hydrogen bonds
Ionic bonds
Covalent bonds

14

What are the conditions and reagents for hydrolysis of proteins?

Mod conc acid/alkali
Reflux

15

How can amino acids be identified?

TLC with ninhydrin locating agent

16

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

Rate= k[E] [S]
First order

17

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

Rate = k[E]
Zero order

18

Why are enzymes used in industry?

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

19

How are reactive metals extracted?

By electrolysis

20

How are less reactive metals extracted?

By reduction with carbon/CO

21

Examples of barrier protection?
What does it prevent?

Paint, grease, oil, polymer coating
Oxygen/water coming into contact with iron and steel

22

What is sacrificial protection?

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

23

What is a transition metal?

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

24

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

4s

25

What are 3 physical properties of d block elements?

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

26

What are the four important chemical properties of transition metals?

Variable oxidation states
Coloured ions
Complexes
Catalysts

27

What is a ligand?

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

28

What is the coordination number?

Number of bonds between ligand and central metal atoms