Science Unit 6 HUMAN DIGESTIVE SYSTEM Flashcards
Living things require food to:
- Provide them energy to do work
- Maintain a healthy body
- Grow new cells and tissues
- Repair worn-out tissues
The three main classes of food:
Fats, Carbohydrates, Proteins
Function and Example of a Carbohydrate
- Provides a primary source of energy for various activities (e.g Growth and Movement)
- Example: Rice, Potatoes, Pasta, Biscuit, Noodles
Function and Example of a Fat
- Provides twice the amount of energy compared to carbohydrates of the same mass
- Stored under the skin to insulate the body from excessive heat loss
Example -> Butter, Cooking Oil, Tuna
Function and Example of a Protein
- Aids the growth of new cells and tissues
- Repair previously damaged tissues
- Serves as a source of energy when Carbs and Fats are unavailable
Example -> Milk, Fish, Egg
Definition of Digestion:
The breaking down of large and complex undigested food substances into small and simple digested food substances.
Fun fact on Small Intestine:
The cell membrane of tissue cells in the intestinal walls is partially permeable.
After action of enzymes, Carbohydrates become?
Glucose
After action of enzymes, Fats become?
Glucerol and Fatty Acids
After action of enzymes, Proteins become?
Amino Acids
What are the two types of Digestion?
- Physical Digestion
- Chemical Digestion
What is Physical Digestion, What is it’s purpose and Where does it occur?
- It is the physical breakdown of large food chunks to smaller pieces to increase the surface area for further digestion.
- No new products are formed since the chemical properties of food substances remain the same.
- Chewing action (Mouth)
- Churning action (Stomach)
What is Chemical Digestion, What is it’s purpose and Where does it occur?
- A process where large and complex food substances are chemically broken down into small and simpler food substances that can enter the bloodstream through the intestinal wall.
- Starch (Mouth & Gullet)
- Proteins (Stomach)
- Carbohydrates, Proteins and Fats (Small Intestine)
What are Proteases and what do they do
- They speed up the breakdown of proteins into amino acids.
Protein -> Proteases -> Amino Acids
Definition of Enzymes:
They are biological molecules that are made of special types of proteins that speed up the rate of chemical digestion
Why do each enzyme only act on one type of substance.
What are Carbohydrases and what do they do:
- Carbohydrases speed up the breakdown of carbohydrates into simple sugars.
Carbohydrates -> Carbohydrases -> Simple Sugars
What are Lipases and what do they do
- Lipases speed up the breakdown of fats (or lipids) into fatty acids and glycerol.
Fats (Lipids) -> Lipases -> Fatty Acids & Glycerol
What is the name of the food substance in which can Enzyme acts on?
The substrate
What is the Human Digestive System:
It is made up of coiled, muscular tube called the alimentary canal (gut)
Organs that make up the ailmentary canal (digestive system):
Mouth, Gullet, Stomach, Small Intestine, Large Intestine, Rectum and Anus
Another name for Digestive system
Ailmentary canal
Function of Saliva
- To soften and lubricate the food for easier swallowing.
- Provide a neutral environment for carbohydrases to function properly
What type of digestive enzyme is found in the saliva in the mouth
Carbohydrases partially dugest starch
Definition of the gullet
A muscular tube that carries food from the mouth to the stomach
Definition of the Stomach
It is a sac-like muscular organ that lies in the upper part of the abdomen.
What are the 3 types of gastric juices secreted in the stomach (HMP)
- Hydrochloric acid
- Mucus
- Proteases
What are the chemical and physical digestion that occur in the stomach?
- Physical digestion: A churning action to break food into smaller pieces, mixes food with gastric juices.
- Chemical digestion: An enzyme called proteases digest protein to get Amino acids
Function of hydrochloric acid (Stomach)
- To kill bacteria in the food
- Provides acid environment for proteases to work well
3 types of environment for the 3 types of digestive enzymes to work well:
- Carbohydrases: Neutral environment
- Lipases: Neutral environment
- Proteases: Acidic environment
Function of mucus (Stomach)
- Prevents hydrochloric acid and proteases from damaging the tissues.
What is the key thing that happens in the small intestine?
Chemical digestion of all classes of food takes place here (Carbohydrates, Fats, Proteins)
What is in the digestive juice in the small intestine:
- Secretionmany enzymes such as carbohydrases, proteases and lipases happens here.
________ of _________ only takes place in the small intestine.
Chemical digestion of fats only takes place in the small intestine.
Which 2 organs facilitate the digestion of fats?
- The liver
- The gall bladder
Bile is produced in the liver and stored in the gall bladder.
What does the rectum do?
- Stores faeces
Length of small intestine:
6 meters. It enhances the efficiency and surface area for complete digestion to take place.
What does bile do?
- It is produced in the liver
- It is not an enzyme
- It breaks up fat molecules into fat globules.
Length of large intestine:
1.4 meters. It enhances process for waste management and hydration balance in the body.
Order of Digestive organs:
Mouth, Gullet, Stomach, Small Intestine, Large Intestine, Rectum, Anus
What does the anus do?
- Removes faeces through a hole, this process is known as egestion
What is type 1 diabetes:
Body produces insufficient insulin
What is type 2 diabetes:
Body does not respond properly to insulin
What are some risk factors associated with Diabetes:
- Obesity
- High Blood Pressure
- Kidney Problems
- Risk of heart attack
- Risk of stroke
Symptoms of Diabetes:
- Blurred vision
- Slow healing of wounds
- Frequent urination
- Unexplained weight lose
- Tingling or numbness in the hands and feet
- Constant hunger
Ways to reduce the risk of Diabetes:
- Exercise regularly
- Eat a balanced healthy diet (Following healthy plate -> Less salt and saturate dfats, more wholegrain and vegetables)
- Avoid smoking or drinking
- Have a regular health screening
- Use a blood sugar meter to monitor blood sugar levels in the body
What is the definition of Constipation:
It occurs when faeces move too slowly through the large intestines, leading to excessive water absorbtion -> Results in dry, hard faeces that may be hard to pass
What are the two life-threatening diseases caused by bacteria
- Cholera
- Salmonella
What is the definition of Gastric pain:
A painful swelling or inflammation of the Stomach lining (Symptoms: Bloating, Nausea, Upper abdominal pain)
What is Enzyme Amylase?
Carbohydrases (Digests starch)
What are the benefits of good bacteria?
- Fight off certain diseases
- Absorb nutrients & Mineral salts
- Produce certain enzymes, vitamins and amino acids
