Nutrition in Man

Nutrition in Man

Small intestine (Duodenum)

• Prepare your

whiteboards!

Let’s Recap!

Let’s Recap!

• Name the three parts of the small intestine

Let’s Recap!

• Name the three parts of the small intestine

1)Duodenum2)Jejunum3)Ileum

Let’s Recap!

• Name the three secretions found in the duodenum

Let’s Recap!

• Name the three secretions found in the duodenum

1)Intestinal Juice2)Pancreatic Juice3)Bile

Lesson Objectives

• To state the 3 secretions found in the small intestine and describe the enzymatic reaction that takes place in the duodenum.

• To understand some of the answering techniques in Science (Biology) questions:– Graphing techniques in science– Task words

Let’s Recall

• The 3 secretions:–Intestinal Juice –Pancreatic Juice–Bile (no enzymes)

Small intestineRegion of digestion

Secretion Source Enzyme Action

Small intestine

BilePancreatic juice

Intestinal juice

Small intestineRegion of digestion

Secretion Source Enzyme Action

Small intestine

Bile Liver - Emulsifies fatPancreatic juice

Pancreas AmylaseProtease (Trypsin)Lipase

Starch maltoseProteins polypeptidesFats fatty acids and glycerol

Intestinal juice

Intestinal glands

MaltaseProtease (Erepsin)Lipase

Maltose glucosePolypeptides amino acids

Fats fatty acids and glycerol

Small intestine

Substrate Enzyme Product/ Substrate Enzyme Product

Starch Pancreatic amylase Maltose Maltase Glucose

Carbohydrate digestion

Small intestineProtein digestion– Some digested in the stomach– Undigested proteins enter small intestine– Converted to polypeptides by protease (trypsin)

Substrate Enzyme Product/ Substrate Enzyme Product

Proteins Protease (Trypsin) Polypeptides Protease

(Erepsin)Amino acids

Small intestineFat digestion– Bile emulsifies fats and breaks them up into

minute fat globules• Enlarges surface area of fats• Speed up digestion

– End products are fatty acids and glycerol

Substrate Enzyme Product

Fats Lipase Fatty acids and Glycerol

Diagram for fat emulsification

big drop of fat

bile salts

tiny fat droplets

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Answering techniques

Graphing in Science

Graph

• Plot a graph (it can be a straight line or a curve depending on your plots) accurately in pencil only.

Graph

• Give an appropriate title to the graph. Example : Graph of rate of reaction against temperature

Graph

• Check that you have gotten the x- and y-axis correct.

E.g. Plot a graph of rate of bubbling against light intensity: the rate of bubbling takes the y-axis and the light intensity takes the x-axis.

Graph

• Label the axes clearly and include units for each axis if applicable.

Graph

• Use appropriate scale for both axes.

• It is alright not to start at zero for both axes if you wish to stretch the curve in order to maximize the space on the graph paper. (3/4 of the space provided)

Graph

• Draw a best-fit curve. Use a flexible curve / free hand for drawing a curve and a ruler for drawing a straight line.

• Try your best to pass the curve / straight line through as many points as possible. (Note: The term ‘curve’ used in plotting of graph in biology can mean an actual curve or a straight line.)

Graph

• Do not extrapolate the curve beyond the first and last point.

Task wordsWords that tell you what you need to

do

List of task words

• Define• State• List• Describe • Explain / Account

• Outline• Suggest• Illustrate• Name / Identify• Discuss• Distinguish

Muddiest Point