Review

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Effects of a poor diet

Some effects of a poor diet (Student A)
Work in pairs: each student has to read the information about two diseases related to a poor diet and complete two rows in the table. After this, share the information with your mate and complete the remaining rows. Use the following expressions to tell your mate the information: results from, comes from, is caused by, can lead to, results in, could be avoided by, …).

Disease	Causes	Effects	Solutions
Constipation
Goitre

Some effects of a poor diet (Student B)
Work in pairs: each student has to read the information about two diseases related to a poor diet and complete two rows in the table. After this, share the information with your mate and complete the remaining rows. Use the following expressions to tell your mate the information: results from, comes from, is caused by, can lead to, results in, could be avoided by, …).

Disease	Causes	Effects	Solutions
Rickets
Anaemia

Extra activity

Calling all junior food detectives!

There has been a mysterious outbreak of unhealthy habits hitting too many boys and girls. If we don't solve these cases, and fast, kids might not make the right food and exercise choices as they grow, and that could be trouble!
All junior food detectives will get secret training on how to eat right and exercise. You can investigate fun games like Whack A Snack, Soccer, and Zap the TV. Plus you can print out classified clues on ways to be healthy, then share them with your parents, teachers, and pals.

Confidentially yours,
the Amazing Food Detective

http://www.primarygames.com/science/nutrition/games/amazingfooddetective/

Self assessment

How much do you know about digestion and the digestive system?

 Pincha aqui: http://www.bbc.co.uk/education/guides/zwqycdm/test

 

Mechanical and chemical digestion

Digestion is the breakdown of carbohydrates, proteins and fats into small soluble substances to be absorbed into the blood. Amylase, proteases and lipases are enzymes that are important in digestion. 

Digestive enzymes

 Digestion is the breakdown of large, insoluble food molecules into small, water-soluble molecules using mechanical and chemical processes. Mechanical digestion includes:

• chewing in the mouth
• churning in the stomach

Chemical digestion involves enzymes. These are proteins that function as biological catalysts

Different enzymes

Enzymes can break down nutrients into small, soluble molecules that can be absorbed. For example, amylase causes the breakdown of starch into simple sugars.

Where enzymes are produced

Enzyme	Substrate	End-products	Where produced
Salivary amylase	Starch	Maltose	Salivary glands
Protease	Protein	Amino acids	Stomach, pancreas
Lipase	Lipids (fats and oils)	Fatty acids and glycerol	Pancreas
Pancreatic amylase	Starch	Maltose	Pancreas
Maltase	Maltose	Glucose	Small intestine

 

Where digestion happens

• Proteases catalyse the breakdown of proteins into amino acids in the stomach and small intestine
• Lipases catalyse the breakdown of fats and oils into fatty aicds and glycerol in the small intestine
• Amylase catalyses the breakdown of starch into maltose in the mouth and small intestine
• Maltase catalyses the breakdown of maltosa into glucosa in the small intestine

 

Pincha aqui: http://www.bbc.co.uk/education/guides/zwqycdm/activity


Maybe, this can hepl you...

Digestive System Glossary:

• abdomen - the part of the body that contains the digestive organs. In human beings, this is between the diaphragm and the pelvis

• alimentary canal - the passage through which food passes, including the mouth, esophagus, stomach, intestines, and anus.

• anus - the opening at the end of the digestive system from which feces (waste) exits the body.

• appendix - a small sac located on the cecum.
• ascending colon - the part of the large intestine that run upwards; it is located after the cecum.

• bile - a digestive chemical that is produced in the liver, stored in the gall bladder, and secreted into the small intestine.
• cecum - the first part of the large intestine; the appendix is connected to the cecum.
• chyme - food in the stomach that is partly digested and mixed with stomach acids.Chyme goes on to the small intestine for further digestion.
• descending colon - the part of the large intestine that run downwards after the
• digestive system - (also called the gastrointestinal tract or GI tract) the system of the
• duodenum - the first part of the small intestine; it is C-shaped and runs from the stomach to the jejunum.
• epiglottis - tthe flap at the back of the tongue that keeps chewed food from going down
  the windpipe to the lungs. When you swallow, the epiglottis automatically closes.
  When you breathe, the epiglottis opens so that air can go in and out of the windpipe.

• esophagus - the long tube between the mouth and the stomach. It uses rhythmic
  muscle movements (called peristalsis) to force food from the throat into the stomach.
• gall bladder - a small, sac-like organ located by the duodenum. It stores and releases bile (a digestive chemical which is produced in the liver) into the small intestine.
• gastrointestinal tract - (also called the GI tract or digestive system) the system of the body that processes food and gets rid of waste.
• ileum - the last part of the small intestine before the large intestine begins.
• intestines - the part of the alimentary canal located between the stomach and the anus.
• jejunum - the long, coiled mid-section of the small intestine; it is between the duodenum and the ileum.

-liver - a large organ located above and in front of the stomach. It filters toxins from the
blood, and makes bile (which breaks down fats) and some blood proteins.
mouth - the first part of the digestive system, where food enters the body. Chewing
and salivary enzymes in the mouth are the beginning of the digestive process (breaking
down the food).
-pancreas - an enzyme-producing gland located below the stomach and above the
intestines. Enzymes from the pancreas help in the digestion of carbohydrates, fats and
proteins in the small intestine.
-peristalsis - rhythmic muscle movements that force food in the esophagus from the
throat into the stomach. Peristalsis is involuntary - you cannot control it. It is also what
allows you to eat and drink while upside-down.
-rectum - the lower part of the large intestine, where feces are stored before they are
excreted.
-salivary glands - glands located in the mouth that produce saliva. Saliva contains
enzymes that break down carbohydrates (starch) into smaller molecules.
-sigmoid colon - the part of the large intestine between the descending colon and the
rectum.
-stomach - a sack-like, muscular organ that is attached to the esophagus. Both chemical
and mechanical digestion takes place in the stomach. When food enters the stomach, it
is churned in a bath of acids and enzymes.
-transverse colon - the part of the large intestine that runs horizontally across the
abdomen.

Activity 1: Name the part of the digestive apparatus where:

- bile is produced: ………………………

- the conditions are acidic: ………………………

- bile is stored: ………………………

- excess water and salts are removed: ………………………

- only protease enzymes are produced: ………………………

- protease, lipase and carbohydrase enzymes are produced:………………………

- digestion is completed here: ………………………

- the carbohydrate starch is broken down by the amylase:………………………

- incisors, molars and canines are found: ………………………

- food and drink go from the mouth down to the stomach:………………………

- absorption of nutrients takes place: ………………………

Activity 2: In the table below decide if the information for each box is true

(T) or false (F).

 

Activity 3: Match the following words to their definitions: