Topic 1 - Biological molecules

Question 1

Phosphate ions are components of … & …

Answer 1

DNA & ATP

Question 2

Sodium ions are involved in …. of glucose and ….

Answer 2

Co-transport & Amino acids.

Question 3

Iron ions are a component of …

Answer 3

Haemoglobin.

Question 4

Hydrogen ions determine the … of substances.

Answer 4

pH.

Question 5

Inorganic ions occur …

Answer 5

In solution in the cytoplasm and body fluid of organisms.

Question 6

What is ATP and what does it stand for?

Answer 6

Adenosine triphosphate is a nucleotide derivative.

Question 7

What makes up ATP?

Answer 7

A ribose, adenine and 3 phosphates.

Question 8

ATP is …. by the condensation of ADP and Pi. This is catalysed by the enzyme …. during photosynthesis or respiration.

Answer 8

Resynthesises & ATP synthase.

Question 9

The inorganic phosphate released by the hydrolysis of ATP can be used to….

Answer 9

Phosphorylates other compounds, often making them more reactive.

Question 10

The enzyme ATP …. catalysed the ….. reaction of ATP to ADP(……. ……..) and …… ….. ……

Answer 10

Hydrolase, hydrolysis, adenosine diphosphate, inorganic phosphate group.

Question 11

Adenosine triphosphate (ATP) is a molecule formed from what?

Answer 11

Adenine, Ribose and 3 phosphate.

Question 12

Describe the test for lipids.

Answer 12

Add ethanol and shake, then add water. A positive result will form a milky/cloudy white emulsion.

Question 13

A) where do the phosphate heads face?
B) are they hydrophilic or hydrophobic?

Answer 13

A) Point outside of the membrane.
B) Hydrophyllic.

Question 14

A) Where do the fatty acid tails face?

B) Are they hydrophilic or hydrophobic?

Answer 14

A) The interior of the membrane.
B) Hydrophobic.

Question 15

Describe the function of the phospholipids related to its structure.

Answer 15

They form a bilayer in the cell membrane, allowing diffusion of lipid, soluble or very small substances and restricting movement of water soluble or larger substances.

Question 16

How are the properties of triglycerides related to their structure?

Answer 16

They have a high ratio of carbon to hydrogen bonds to carbon atoms in hydrocarbon chains which is useful for respiration to release more energy.

Question 17

What is the function of triglycerides?

Answer 17

Energy storage.

Question 18

Describe the differences between the structure of triglycerides and phospholipids?

Answer 18

One of the fatty acids of a triglyceride is subsisted by a phosphate group.

Question 19

The … of a fatty acid can be saturated or unsaturated

Answer 19

The R-group.

Question 20

How do triglycerides form?

Answer 20

Glycerol joins with three fatty acids which are joined by a condensation reaction forming three ether bonds. The reaction is between the one fatty acid and one glycerol which is the R COOH.

Question 21

What does unsaturated mean?

Answer 21

One or more carbon-carbon double bond in the hydrocarbon chain.

Question 22

What does saturated mean?

Answer 22

There is no carbon-carbon double bonds in the hydrocarbon chain.

Question 23

Name the two groups of lipids.

Answer 23

Triglycerides and phospholipids.

Question 24

What are monosaccharides?

Answer 24

Monomer from which larger carbohydrates are made.

Question 25

Give three of the most common monosaccharides?

Answer 25

Glucose galactose and fructose.

Question 26

A condensation reaction between two monosaccharides forms what bond?

Answer 26

Glycosidic.

Question 27

How are disaccharides formed and by which reaction?

Answer 27

The joining of two monosaccharides by a condensation reaction.

Question 28

Give three common disaccharides.

Answer 28

Maltose lactose and sucrose.

Question 29

...... + ....... = maltose ...... + ....... = sucrose ...... + ....... = lactose

Answer 29

Glucose + glucose. Glucose + fructose. Glucose + galactose.

Question 30

What is Watson & Crick's theory based on?

Answer 30

The specific hydrogen bonding between pairs of nitrogenous bases being used during replication to conserve the genetic sequence.

Question 31

What model did Watson and Crick discover?

Answer 31

A model by which DNA might be replicated (called semi-conservative DNA replication).

Question 32

What did Watson and Crick confirm and in what year?

Answer 32

The double helix structure of DNA - 1953.

Question 33

Explain the process of semi-conservative replication of DNA.

Answer 33

First is the unwinding of the double helix and then the breakage of the hydrogen bonds between the polynucleotide strands. The role of DNA had a case is unwinding the DNA by breaking the hydrogen bonds. Attraction of new DNA nucleotides to expose bases on the template strands. The role of DNA polymerase in the condensation reaction that joins adjacent nucleotides.

Question 34

Compare DNA to RNA. 3 marks.

Answer 34

DNA - deoxyribose, double stranded, thymine. RNA - ribose, single stranded, uracil.

Question 35

What does semi-conservative replication of DNA ensure?

Answer 35

Genetic continuity between generations of cells.

Question 36

Due to the simplicity of the DNA, many scientists doubted what?

Answer 36

That it carried the genetic code.

Question 37

RNA is a relatively ... polynucleotide chain.

Answer 37

Short.

Question 38

A DNA molecule is a ... shape, with two ... chains held together by ... between the ...

Answer 38

Double helix. Polynucleotide. Hydrogen. Base pairs.

Question 39

A ... reaction between two nucleotides forms a phosphodiester bond.

Answer 39

Condensation.

Question 40

Name the three components of RNA.

Answer 40

Ribose, phosphate group and an organic base.

Question 41

Name the 4 organic bases.

Answer 41

Adenine, Thymine, Guanine and cytosine.

Question 42

Draw and label a nucleotide.

Answer 42

---

Question 43

DNA and RNA are ... of nucleotides.

Answer 43

Polymers.

Question 44

What are the two components in which a ribosome is formed from?

Answer 44

RNA and proteins.

Question 45

What bonds join adjacent nucleotides in DNA?

Answer 45

Phosphodiester.

Question 46

In the structure of DNA, each nucleotide is formed from what 3 things?

Answer 46

Deoxyribose, phosphate group, organic base.

Question 47

DNA holds ... ... and RNA ... genetic information from ... to the ...

Answer 47

Genetic information - transfers - DNA - ribosomes.

Question 48

Suggest a safety risk and explain how to reduce this risk in the enzyme required practical.

Answer 48

Handling enzymes may cause allergic reactions which means you'll need to avoid contact with skin by wearing gloves and using protection.

Question 49

Explain why using a colour to measure the colour changes better than comparison to colour standards.

Answer 49

Not subjective and much more accurate giving a quantitative value.

Question 50

Why were the enzymes and substrate solutions left in a water bath for 10 minutes before mixing in the enzyme required practical?

Answer 50

To allow solutions to equilibrate and reach the temperature of the water bath.

Question 51

Describe how pH can be controlled in required practical one?

Answer 51

Use a buffer solution and monitor use a pH meter.

Question 52

Describe how temperature can be controlled and require practical one?

Answer 52

Use a statically controlled water bath and monitor using a thermometer at regular intervals.

Question 53

Give examples of variables that affects the rate of enzyme controlled reactions.

Answer 53

Enzyme concentration, substrate concentration, temperature, pH and inhibitor concentration.

Question 54

Describe and explain the effect of non-competitive inhibitors on the rate of enzyme controlled reactions

Answer 54

As concentration of the non-competitive inhibitor increases, the rate of reaction decreases.

Question 55

Describe and explain the effect of competitive inhibitors on the rate of enzyme controlled reactions.

Answer 55

As concentration of the competitive inhibitors increases the rate of reaction decreases due to competition.

Question 56

What makes an enzyme be classed as denatured?

Answer 56

Changes to the tertiary structures and active site changes the shape.

Question 57

Describe and explain the effective pH on enzyme controlled reactions.

Answer 57

As the pH increases the rate of reaction increases until optimum temperature and then it will decrease due to enzymes denaturing.

Question 58

Describe and explain the effect of temperature on the rate of enzyme controlled reactions.

Answer 58

As temperature increases to optimum the rate of reaction increases as more kinetic energy and more enzyme substrate complexes form. Above optimum temperature the rate of reaction decreases due to enzymes denaturing creating an inverted U-shaped graph.

Question 59

Describe and explain the effect of substrate concentration on the rate of enzyme controlled reactions.

Answer 59

As substrate concentration increases the rate of reaction increases.

Question 60

Describe and explain the effective enzyme concentration on the rate of enzyme controlled reactions.

Answer 60

As the enzyme concentration increases, the rate of reaction increases.