Week 4

Question 1

Ostwarld ripening

Answer 1

This is the phenomenon where smaller droplets coalesce into larger ones because of the pressure difference

Question 2

Coalescence

Answer 2

Two droplets or air bubbles can become one when their films/surface combine. Usually and emulsifier keeps the droplets separate, but if the emulsifier layer is incomplete or not thick enough, the bubbles can combine

Question 3

Partial coalescence

Answer 3

This is where two droplets combine partially because the have a crystalline structure inside which prevents a full coalescence

Question 4

Creaming

Answer 4

Fat globules/droplets float to the surface of a liquid

Question 5

Aggregation

Answer 5

When two droplets come together into a bundle but do not coalesce. This can be reversed

Question 6

Foam

Answer 6

this is an emulsion of a liquid matrix with air incorporated in

Question 7

Film

Answer 7

this is the barrier around each droplet

Question 8

Film thickness

Answer 8

The thickness of the film is determined by if and how much emulsifier surround the droplet

Question 9

Water-holding capacity

Answer 9

This refers to the amount of water molecules a substance can hold. It is the amount of water molecules that can be held, defying gravity through cohesion forces.

Question 10

Drainage

Answer 10

This is what happens in a foam when the liquid in the matrix drains out from around the air bubble because of gravity. This makes the foam less stable

Question 11

Loop

Answer 11

A loop is the outward facing protein strand loop or circle that extends out from the droplet. It is used to bind with water molecules to help emulsify the incompatible materials.

Question 12

Train

Answer 12

A train is similar to a loop in that its a looping/circular strand of protein used to emulsify a solution. The difference is that the train has most of its surface area facing the droplet. Most of the train is bound to the droplet

Question 13

Tail

Answer 13

The tail is a long strand of protein that reaches out into the bulk water to bind with it. It increases the interactions that the water has with the droplet, reducing surface tension, and this keeps the droplet suspended

Question 14

Carbohydrate

Answer 14

A carbohydrate is a hydrated chain of carbons. It can be anywhere from three to six carbons in length and can have a number of different conformations to make up different sugars. A three carbon chain would be a triose, a four would be a tetrose, a five would be a pentose, and a six would be a hexose. Carbohydrates are either ketones or aldehydes depending on where the carbonyl group falls relative to the anomeric carbon or carbon number one. Carbohydrates form ring structures through a dehydration synthesis reaction of the hydroxyl group on carbon number 5 and the carbonyl carbon or carbon number 1. Depending on if the carbohydrate is a ketose or an aldose controls whether the ring is a pyranose, six molecule ring, or a furanose, a five molecule ring.

Question 15

Monosaccharide

Answer 15

A monosaccharide is a singular carbohydrate unit. They can form glycosidic bonds with other carbohydrates or other molecules. These bonds are called glycosidic bonds. The three monosaccharides are glucose, fructose, and galactose. These combine to make many other compounds.

Question 16

Chiral

Answer 16

A chiral center or chiral carbon in the case of carbohydrates, is a molecule that is bound to four distinct groups bonded together in such a way that they are not superimposable. Chiral centers are mirror images dealing with singular atoms like carbon atoms. This differs from an enantiomer because enantiomers are whole molecules that are mirror images of each other rather than individual atoms.

Question 17

D-sugar

Answer 17

A d-sugar is a sugar that has the last hydroxyl group on a chiral center pointing right or downwards. In a ring structure this makes the CH2OH group point upwards though.

Question 18

L-sugar

Answer 18

An L sugar has the last hydroxyl group on a chiral center, most often on c-5, which points left on an open chain or Fischer projection, and up in a Haworth projection. This means that the CH2OH group however is pointing down in ring structure.

Question 19

Aldose

Answer 19

An aldose is a carbohydrate that has an aldehyde group for carbon number 1. These structures usually form pyranose rings or rings with the same amount of atoms as there are carbons.

Question 20

Ketose

Answer 20

A ketose is a monosaccharide that has a carbonyl group for carbon number 2 and a CH2OH group for carbon number 1. Ketoses result in ring structures that have one less atom in the ring than they have carbons.

Question 21

Enantiomer

Answer 21

An enantiomer is a molecule that is a mirror image of another. It cannot be superimposed onto another molecule and match up perfectly. Enantiomer = hands. Hands are structured the exact same way but they are mirrored and thus if you put one hand on top of the other, they do not match up. That is the same with carbohydrates, a hydroxyl group could be structured the same, but on the opposite side and thus cannot be superimposed perfectly. Enantiomers deal with whole molecules. The whole molecule is a mirror image of another.

Question 22

Epimer

Answer 22

An epimer is a monosaccharide unit that has had one of the hydroxyl-hydrogen groups switched on a chiral center carbon. For example, glucose is an epimer of of allose on carbon number three

Question 23

Anomer

Answer 23

An anomer is like an epimer where the molecules or switched around a chiral center, but the anomer only deals with the carbon around the hemiacetal/acetal carbon or the ANOMERIC carbon. This different epimer causes a cyclical monosaccharide to either be a beta or an alpha molecule. Anomer - anomeric - alpha/beta

Question 24

Conformation

Answer 24

Conformation refers to the way that molecules are oriented around the chiral center WITHOUT the breaking of bonds. This allows molecules to find the conformation with the least amount of steric strain. This is like if a molecule is in an axial position or an equatorial position.

Question 25

Configuration

Answer 25

Configuration is the breaking of bonds like with epimers and anomers. This causes the molecule to take on completely different properties.

Question 26

Fischer projection

Answer 26

A Fischer projection is an open chain way of depicting a molecule. It is a chain with the carbonyl group towards the top and the CH2OH group at the bottom. The carbons are numbered from top to bottom. The orientation of the hydroxyl group on both the first chiral carbon and the last are important for describing if the saccharide is a D or L, or an alpha or beta anomer.

Question 27

Ring form

Answer 27

The ring form is the cyclical, and in most cases, the natural arrangement of the saccharide. It is formed when the hydroxyl group on the last chiral carbon and the oxygen on the carbonyl carbon come together in a dehydration reaction to form a ring. Usually only four, five, and six carbon chains are able to form rings. There is too much steric strain for a three carbon chain to form a ring

Question 28

Pyranose

Answer 28

Pyranose is a ring with six atoms in it. It has as many atoms as it has carbons.

Question 29

Furanose

Answer 29

Furanose is a ring with five atoms in it. It usually has one less atom in the ring than it has carbons.

Question 30

Isomerization

Answer 30

An isomerization is where some bonds are broken and the molecule is reconfigured to have a different functional group. This can be seen with the isomerization of an aldose to a ketose and vice versa

Question 31

Mutarotation

Answer 31

Mutarotation is where the bonds rotate around a chiral center to present a certain optical angle. This is where beta and alpha anomers come in.

Question 32

Tautomer

Answer 32

A tautomer is where the structure of molecules is the same, they differ only in the position of the protons and the electrons. If a hydrogen or proton is transferred for example, and a carboxylic acid became a carboxylate, that would be a tautomerization.