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
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 fat
Pancreatic 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
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
• 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.)
List of task words
• Define• State• List• Describe • Explain / Account
• Outline• Suggest• Illustrate• Name / Identify• Discuss• Distinguish