Chemistry

Question 1

What does hydrophobic mean?

Answer 1

Repels water

Question 2

What does hydrophilic mean?

Answer 2

Attracts water

Question 3

What are the characteristics of alpha amylase?

Answer 3

64-68°C
5.3-5.5 pH
Requires calcium as a cofactor that’s increases the heat tolerance

Question 4

What are the characteristics of beta amylase?

Answer 4

60-65°C
5.0-5.5 pH
Does not require calcium

Question 5

What is alkalinity vs hardness

Answer 5

Hardness describes the amount of divalent ions in solution (mg+2, ca+2). Alkalinity is the ability of water to resist changes to ph with acids - usually via carbonate.

Question 6

What is turbidity?

Answer 6

A measure of light blocking particles in solution.

Question 7

What is a collagen?

Answer 7

Protein molecules derived from animal tissue

Question 8

What is isinglass?

Answer 8

Collagen
Positive charge at beer pH
Swim bladder of a tropical fish

Question 9

What is gelatin?

Answer 9

Collagen
Contains animal products (not vegan)
Precipitates yeast via electric charge
Precipitates polyphenols via hydrogen bond

Question 10

What is a polypeptide?

Answer 10

A molecule made up of less than 50 amino acids

Question 11

What is a protein?

Answer 11

A molecule made up of more than 50 amino acids.

Question 12

What is a polyphenol?

Answer 12

Derived from plants
Phenolic characteristics
More soluble in high pH
Eg. tannic acid
Aka tannins

Question 13

What is brewtan?

Answer 13

Tannic acid
Precipitates proteins through adsorption
Effective on proline and thiols

Question 14

What is the diacetyl pathway?

Answer 14

Glucose to pyruvate to a-acetolactate to produce valine.
A-acetolactate migrates out of the cell and oxidizes to diacetyl.
Diacetyl may migrate back into the cell and be broken down to acetoin and 2,3-butanediol or converted into valine.

Question 15

What is a maillard reaction?

Answer 15

A reaction between a sugar and a protein is then dehydrated with heat to create a flavor compound similar to caramel or toffee

Question 16

What is strecker degradation?

Answer 16

A reaction between dicarbonyl compounds and amino acids to produce an aldehyde with burnt, astringent, toasty, and nutty flavors.

Question 17

What is the Crabtree effect?

Answer 17

In the presence of high levels of glucose (0.4%), despite the oxygen concentration, yeast will favor the anaerobic fermentation pathway instead of the aerobic respiration pathway.

Question 18

What is brewers clarex?

Answer 18

A proline specific endo-protease that prevents chill haze.

Question 19

What is Henry’s law?

Answer 19

The amount of dissolved gas in a liquid is directly proportional to its partial pressure above the liquid.

Question 20

What is Dalton’s law?

Answer 20

The total gas pressure in a tank is equal to the sum of the partial pressures of each gas.

Question 21

What is the difference between a covalent bond and an ionic bond?

Answer 21

Covalent is the sharing of electrons between 2 non metal atoms. Very strong.
Ionic is the sharing of electrons between a metal and non metal (salt). Not as strong.

Question 22

What is an amino acid?

Answer 22

Building block of proteins.
Consist of a carboxyl group, methyl group with only one hydrogen, followed by an amino group.

Question 23

What are the base pairs in DNA?

Answer 23

A-T
G-C

Question 24

What are the 3 enzymes in DNA replication?

Answer 24

Helicase - separates DNA
Topoisomerase - unwinds DNA
DNA polymerase - replicates other half as RNA

Question 25

What is Boyle’s law?

Answer 25

Pressure and volume are inversely proportional if temperature is held constant.
T=PV

Question 26

What is Charles law?

Answer 26

The volume of a gas varies directly with temperature at a constant pressure.
P=T/V

Question 27

What is the ideal gas law?

Answer 27

PV=nRT
Pressure (atm)
Volume (L)
Moles of gas present
Constant (0.0821atmL/molK)
Temperature (K)

Question 28

What is amylose bs amylopectin?

Answer 28

Amylose is unbranched starch (only 1-4 links), amylopectin has branches (occasional 1-6 links)