brainscape_flashcards_topic1_full

Question 1

What is a monomer?

Answer 1

A small molecule that can join with other molecules to form a polymer.

Question 2

What is a polymer?

Answer 2

A large molecule made up of many monomers joined together.

Question 3

What reaction forms polymers?

Answer 3

Condensation reaction - joins molecules and releases water.

Question 4

What reaction breaks down polymers?

Answer 4

Hydrolysis reaction - breaks chemical bonds using water.

Question 5

What is a monosaccharide?

Answer 5

A single sugar unit; monomer of carbohydrates.

Question 6

Give three common monosaccharides.

Answer 6

Glucose, fructose, galactose.

Question 7

What is the difference between α-glucose and β-glucose?

Answer 7

OH on carbon 1 is below in α-glucose, above in β-glucose.

Question 8

What is a disaccharide?

Answer 8

Two monosaccharides joined by a glycosidic bond in a condensation reaction.

Question 9

Name three disaccharides and their components.

Answer 9

• Maltose = glucose+glucose,
• Sucrose = glucose+fructose,
• Lactose = glucose+galactose.

Question 10

What is a polysaccharide?

Answer 10

A carbohydrate made up of many monosaccharides joined by glycosidic bonds.

Question 11

Describe the structure of starch.

Answer 11

Polysaccharide of α-glucose: amylose (unbranched), amylopectin (branched).

Question 12

Why is starch a good storage molecule?

Answer 12

Compact, insoluble, and easily hydrolysed.

Question 13

Describe the structure of glycogen.

Answer 13

Highly branched polymer of α-glucose.

Question 14

Why is glycogen suited for energy storage in animals?

Answer 14

Highly branched for fast hydrolysis; compact and insoluble.

Question 15

Describe the structure of cellulose.

Answer 15

Polymer of β-glucose with straight chains linked by hydrogen bonds into microfibrils.

Question 16

Why is cellulose strong?

Answer 16

Many hydrogen bonds form strong microfibrils.

Question 17

Describe the Benedict’s test for reducing sugars.

Answer 17

Add Benedict’s solution and heat; positive = red/orange/yellow/green precipitate.

Question 18

How do you test for non-reducing sugars?

Answer 18

Hydrolyse with acid, neutralise, then redo Benedict’s test.

Question 19

How do you test for starch?

Answer 19

Add iodine solution; positive = blue-black.

Question 20

How can you estimate sugar concentration?

Answer 20

Use Benedict’s test, filter, dry and weigh precipitate or use a colorimeter.

Question 21

How does a colorimeter help measure sugar concentration?

Answer 21

Measures absorbance of light through solution; use calibration curve to determine unknown.

Question 22

What is a triglyceride?

Answer 22

A lipid made of 1 glycerol and 3 fatty acids.

Question 23

What bond forms in triglycerides?

Answer 23

Ester bond.

Question 24

What is the difference between saturated and unsaturated fatty acids?

Answer 24

Saturated = no C=C bonds; Unsaturated = one or more C=C bonds.

Question 25

What is a phospholipid?

Answer 25

A lipid where one fatty acid is replaced by a phosphate group.

Question 26

Why are phospholipids important in membranes?

Answer 26

Form bilayers; heads are hydrophilic, tails hydrophobic.

Question 27

Describe the emulsion test for lipids.

Answer 27

Add ethanol, shake, add water; positive = milky white emulsion.

Question 28

What is the general structure of an amino acid?

Answer 28

Amine group (NH2), carboxyl group (COOH), R group.

Question 29

How do amino acids join?

Answer 29

Condensation reaction forming peptide bonds.

Question 30

What is the primary structure of a protein?

Answer 30

The sequence of amino acids.

Question 31

What is the secondary structure?

Answer 31

Folding into α-helix or β-pleated sheets via hydrogen bonds.

Question 32

What is the tertiary structure?

Answer 32

3D folding due to R group interactions (H bonds, ionic bonds, disulfide bridges).

Question 33

What is the quaternary structure?

Answer 33

Protein structure with more than one polypeptide chain.

Question 34

Describe the Biuret test for proteins.

Answer 34

Add NaOH and CuSO4; positive = purple color.

Question 35

How do enzymes speed up reactions?

Answer 35

Lower the activation energy.

Question 36

Describe the induced fit model.

Answer 36

Substrate binding changes active site shape to fit more closely.

Question 37

Why are enzymes specific?

Answer 37

Tertiary structure of active site is complementary to one substrate.

Question 38

What affects enzyme activity?

Answer 38

Temperature, pH, substrate and enzyme concentration.

Question 39

What happens to enzymes at high temperatures?

Answer 39

They denature; bonds break, active site changes.

Question 40

What is a competitive inhibitor?

Answer 40

Molecule similar to substrate competes for active site.

Question 41

What is a non-competitive inhibitor?

Answer 41

Binds to allosteric site, changing enzyme shape.

Question 42

What variables affect enzyme reactions?

Answer 42

Temperature, pH, enzyme and substrate concentration, inhibitors.

Question 43

How to measure rate of enzyme reaction?

Answer 43

Measure product/substrate change over time; rate = 1/time.

Question 44

How to stop enzyme reactions?

Answer 44

Boil, add strong acid/alkali, use inhibitor.

Question 45

Why use a colorimeter in enzyme experiments?

Answer 45

More accurate and objective than color matching.

Question 46

What is DNA made of?

Answer 46

Two antiparallel strands of nucleotides with phosphodiester bonds.

Question 47

What is RNA made of?

Answer 47

Single strand of nucleotides; ribose sugar; uracil instead of thymine.

Question 48

How does DNA replicate?

Answer 48

Semi-conservative replication using DNA helicase and polymerase.

Question 49

What enzyme forms phosphodiester bonds in DNA replication?

Answer 49

DNA polymerase.

Question 50

What is ATP?

Answer 50

Adenosine triphosphate - energy currency of cells.

Question 51

How is ATP broken down?

Answer 51

Hydrolysis by ATP hydrolase to ADP + Pi.

Question 52

How is ATP made?

Answer 52

Condensation of ADP + Pi by ATP synthase during respiration/photosynthesis.

Question 53

Why is ATP useful?

Answer 53

Releases small, manageable energy amounts quickly.

Question 54

Why is water a good solvent?

Answer 54

It dissolves many polar substances.

Question 55

Why is water important in temperature control?

Answer 55

High specific heat capacity buffers changes.

Question 56

What makes water cohesive?

Answer 56

Hydrogen bonding between molecules.

Question 57

Roles of hydrogen ions in biology?

Answer 57

Affect pH and enzyme activity.

Question 58

Roles of iron ions?

Answer 58

Bind oxygen in haemoglobin.

Question 59

Roles of sodium ions?

Answer 59

Co-transport of glucose/amino acids; nerve impulses.

Question 60

Roles of phosphate ions?

Answer 60

Part of ATP, DNA, RNA, and phospholipids.