CHEM 181 Topic 4.docx - CHEM 181 Topic 4 Lesson 1...

CHEM 181 Topic 4
Lesson 1: Carbohydrates
Video 1
 Macronutrients – carbohydrates, fats, and proteins
o Fat – 65 g/day (more likely 100)
o Protein – 60 g/day (more likely 100)
o Complex carbohydrates – 240 g/day (more likely 300)
o Sugar – 50 g/day
 Amounts to less than 1lb
 Carbohydrates – 4 calories per gram (48% of all calories)
 Proteins – 4 calories per gram (16% of all calories)
 Fats – 9 calories per gram (36% of all calories)
 Fiber – 2 calories per gram
 From 1970 to 2006, about an 11% increase in pounds of food consumed per week
o Dairy has gone down about 20%
o Meat/eggs up 11%
o Sugar up 17%
o Fruit up 26%
o Grains up 42%
o Fats up 59%
Video 2
 The body converts carbohydrates into glucose
 Class carbohydrate is sucrose (table sugar)
o C
12
H
22
O
11
o 4 calories per gram of material
o 2 fragments to sucrose molecule – monosaccharides glucose and fructose which
form the disaccharide sucrose
 A disaccharide consists of two carbohydrate molecules whereas a
monosaccharide consists of one
 Eight -OH groups in a sucrose molecule
o Implies that it is soluble in water (like dissolves like) because –OH groups bind
with water
Video 3
 Our bodies use carbohydrates to create energy
 Energy + H
2
O + CO
2
→ carbohydrates + O
2
(glucose)
o Glucose molecules are oxidized (consumed), giving back water and CO
2
in a cyclic
fashion
 Glucose is composed in the same fashion as sucrose, just as a C
6
monosaccharide
 Stereochemistry – 3D aspect of chemistry and molecular structures
Video 4
 Methane – CH
4
– tetrahedral
o Carbon can bind to itself very effectively

 When you change an –OH group, you change the name of the sugar itself
Video 5
 Cellulose – cannot be digested by humans, but can be by cows
 Starch – can be digested by humans
o Bonding between glucose molecules is different in both
 Enzyme has a specific shape that fits with the reactant molecule and when they combine
that enzyme acts in such a fashion that breaks apart molecules
 Complete oxidation of glucose:
o C
6
H
12
O
6
+ 6O
2
→ 6CO
2
+ 6H
2
O (also energy)
Video 6
 Glucose – also known as Dextrose
 When glucose and fructose are bound together, form sucrose (disaccharide)
o That bond can be broken by an enzyme into the two monosaccharides
 The enzyme has an ASE ending, which is typical of any enzyme engaged in
a process of breaking down any molecules
 Invertase
 Invert sugar – 50/50 glucose and fructose
o Name has to do with optical rotation of mixture
 Maltose is a sugar made up of two glucose molecules
o Maltase is the enzyme that breaks down maltose
 Maltase breaks the carbohydrate into two glucose molecules which are
then converted to energy through complete oxidation
Video 7
 Fructose is sweeter than sucrose and glucose so it’s used as an individual sweetener
o Honey has high percentage of fructose (39%) and low percentage of sucrose (1%)
 Sucrose makes up brown sugar (with molasses)
