Carbohydrates

Monosaccharides

-1 sugar unit
-Glucose fructose, galactose
-All have the same empirical formula (C6H12O6)

Sacchride

Sugar

Glucose fructose, galactose

What are examples of monosacchrides?

Disaccharides

-2 sugar units
-Lactose, sucrose, maltose

Lactose, sucrose, maltose

What are examples of disaccharides?

Oligosacchrides

-3-10 sugar units
-Maltodextrin

Oligosacchride

Maltodexrin is an example of a ___________________

Polysaccharides

->10 sugar units
-Starch, glycogen, fiber

Starch, glycogen, fiber

What are examples of polysaccharides?

Glucose

Dextrose

Glucose is also called _____________

Hexagon

What shape is a glucose molecule?

Fructose

Pentagon

What shape is a fructose molecule?

Galactose

Hexagon

What shape is a galactose molecule?

They contain 6 carbons

Monosaccharides are called hexoses, what does that mean?

The arrangement of the atoms which gives them a slightly different shape

What is the difference between the monosaccharides?

Two

Disaccharides are just _________ monosaccharides bonded together

Fructose and glucose

Sucrose consists of what two monosaccharides?

2 glucose molecules

Maltose consists of what two monosaccharides?

Galactose and glucose

Lactose consists of what two monosaccharides?

Few

Oligosaccharides are a __________ monosaccharides bonded together

Many

Polysaccharides are ________ monosaccharides bonded together

Polysaccharides, oligosaccharides, disaccharides, monosaccharides

What is the order of classes of carbohydrates from largest to smallest?

Fructose is different because it has a pentagon shape and the others have a hexagon shape

Which monosaccharide is different from the others and why?

True

T/F Polysaccharides can form many different shapes

Because glucose molecules can bond or joint together in a few different ways

How do monosaccharides form so many different shapes?

Increasing order starting from the oxygen and going clockwise

How are carbon molecules labelled?

Bonding 1 --> 4

Joins the #1 carbon on one glucose with the #4 carbon on a second glucose

Bonding 1 --> 6

Joins the #1 carbon on one glucose with the #6 carbon on a second glucose

Stereoisomers

Compounds with the same structural formula but with a different arrangement of the atoms in space.

Hydrogen and hydroxide groups at the #1 carbon

Alpha and beta glucose molecules are identical except for what?

Two forms of glucose

Down

Alpha glucose has the hydroxide group pointing __________

Up

Beta glucose has the hydroxide group pointing __________

Left

The isomer of glucose on the _______ tells you which type of bond they will have

Alpha

If the alpha glucose is on the left it will have an ____________ bond

Beta

If the beta glucose is on the left it will have an ____________ bond

An alpha glucose is on the left so it is an alpha bond and the #1 and #4 carbons are connected so we have a alpha (1-->4) bond
*The OH group of the alpha glucose is pointing down and so does the alpha bond

What kind of bond is happening in this picture?

A beta glucose is on the left so it is a beta bond and the #1 and #4 carbons are connected so we have a beta (1-->4) bond
*The OH group of the beta glucose is pointing up and so does the beta bond

What kind of bond is happening in this picture?

Down, up

Alpha bonds point _________ and beta bonds point ________

A Beta (1-->6) bond

What kind of bond is happening in this picture?

Away

In a beta (1-->6) bond the OH groups point _______ each other

Towards

In a alpha (1-->6) bond the OH groups point _______ each other

Alpha (1-->6) bond

What kind of bond is happening in this picture?

Alpha

Starches and glycogen contain what kind of bonds?

Beta

Fiber contains _________ bonds

We lack the enzyme to break down beta bonds so therefore fiber cannot be broken down

Why can't we break down fiber?

Straight

1-4 bonds occur in ________ sections of a polysaccharide

Branches

1-6 bonds occur at ___________

Slower, slower

More complex branching means ______________ digestion and release of glucose resulting in ___________ rise in blood glucose

4

1 gram of carbs equals how many kcal?

45-65%

AMDR of a carbohydrate is what percentage range?

Glucose storage

Glycogen:
-Liver- 100g
-Muscle- 400g
Glucose:
-Blood- 3 g
503g x 4 kcal/g = 2012 kcal

Dextrose because it is a simple sugar and absorbed quickly compared to starch

Will dextrose or starch cause blood sugar and insulin to spike?

Fructose and glucose

All fruits contain what two monosaccharides?

Sucrose and starch

Some fruits contain ______________ and ______________

The purpose of digestion is to break macronutrients down into their smallest components so they can be absorbed

What is the purpose of digestion?

Glucose

What is the smallest component or unit of carbohydrates?

Mouth, stomach, small intestine

Digestion occurs in what three locations?

Lumen

In the small intestine digestion occurs in the __________

Epithelial cells

In the small intestine absorption occurs in the _____________ ______

-Mechanical digestion (chewing)
-Salivary enzymes

What are the two types of digestion that occur in the mouth?

Oral enzymes continue to work

What is happening in the esophagus?

4-8 seconds

How long does it take for food to travel from mount to stomach?

-Mechanical digestion: peristalsis
-Gastric enzymes

What are the two types of digestion that occur in the stomach for carbohydrates?

HCl which is very acidic

What substance is the stomach filled with?

No

Do all macronutrients have both types of digestion in the stomach?

-Pancreas releases pancreatic juice which is a combination of bicarbonate which neutralizes the pH and pancreatic enzymes
-Releases mucus that protects the intestinal lining

What is happening in the small intestine?

Intestinal lumen

Where do pancreatic enzymes continue to break down macronutrients?

Villi, intestinal epithelial cells

The small intestine contain ____________ which contain many ______________

Absorption

Process of transporting broken down nutrients into either the bloodstream or lymphatic system through IEC

Intestinal epithelial cells

Where does absorption take place?

Liver

The Hepatic portal vein beings all nutrients absorbed by the small intestine to the _________ for processing before nutrients can enter the general circulation

Lymphatic

The ___________ system also brings all nutrients to the liver first for processing from the small intestine

Carb digestion (mouth)

-Salivary amylase
-Mastication, mechanical digestion (chewing)

Carb digestion (stomach)

-Ceases due to acidity
-Mechanical digestion

-Pancreatic Amylase
-Intestinal Maltase
-Intestinal Sucrase
-Intestinal Lactase

What are the four enzymes that help breakdown carbs in the small intestine?

Disaccharides

Amylase breaks down oligosaccharides and polysaccharides into what?

Two glucose molecules

Maltase breaks down maltose into what?

A fructose and a glucose molecule

Sucrase breaks down sucrose into what?

Glucose and galactose

Lactase breaks down lactose into what?

Absorption in the small intestine

The IEC are in charge of what?

Monosaccharides

IEC only absorb what?

Galactose and fructose

What two monosaccharides are processed by the liver?

Glucose

______________ is the only monosaccharide to leave the liver and enter general circulation

They are excreted in the feces

What happens to unabsorbed carbs?

Insoluble fiber cannot be digested and acts as a bulking agent and soluble fiber is digested by bacteria residing in the small intestine

What happens to fiber in the digestion and absorption process?

Sucrose

What is the sweetest disaccharide?

Fructose

What is the sweetest monosaccharide?

As the polysaccharide glycogen in our liver and muscle

What is the primary way we store carbohydrates?

Chewing makes the food have more surface area which makes it easier for the digestive enzymes to break it down further

Why is chewing important?

Gastric

Peristalsis helps the ____________ enzymes do their job

When small intestine gets stomach contents it is very acidic, so the small intestine protects itself with pancreatic juice and mucus

Why is pancreatic juice and mucus important?

They increase the surface area of the inside of the small intestine

Why are villi important?

False, digestion will take a pause in the stomach because the salivary amylase will die when it hits the stomach acid

T/F Digestion occurs in the stomach

The liver

Where do digested nutrients go first?

SGT1

Sodium glucose transporter 1

Brings glucose and galactose into the IEC from the lumen

What does SGT1 do?

GLUT5

Glucose transporter 5

Brings fructose into the IEC from the lumen?

What does GLUT5 do?

Because the monosaccharides are different shapes

Why is there two different transporters at the lumen side of an IEC?

GLUT2

What transporter brings the monosaccharides from the IEC to the bloodstream?

True

T/F GLUT2 brings across all the monosaccharides and doesn't care about shape