Digestion

Question 1

What is the function of the bio molecules in the body?

Answer 1

Carbohydrates- the body’s primary source of energy. Broken down into glucose which is then used by cells for respiration.
Fats (lipids)- provide a concentrated energy source. plays a role in the cell membrane structure. Provide essential fatty acids which are necessary for body functions.
Proteins- provide a source of energy when carbs/lipids are insufficient. Maintaining fluid balance. Repair tissues.

Question 2

What happens if you have too much of these bio molecules and if you have too little-

Answer 2

Fats (lipids) - overconsumption of unhealthy fats (saturated, trans fats) can lead to cardiovascular diseases such as a heart disease, stroke,obesity.
Severe deficiency of fats can lead to dry skin, impaired brain function.

Carbohydrates- overconsumption of carbohydrates (refined sugars, etc) can lead to obesity, type 2 diabetes, metabolic syndrome.
Very Low carb intake can lead to low blood sugar levels which causes confusion and weakness.

Proteins- over consumption of proteins can strain your kidneys over time causing the kidneys to be damaged or even result in kidney stones.
Very Low protein intake can lead to malnutrition, impaired immune function and muscle wasting.

Question 3

State the colour changes for all the food tests-

Answer 3

Iodine test for starch- turns from orangey- brown to blue- black if iodine is present. (Positive result) stays orangey- brown if no starch present. ( negative result)
Benedict’s test for sugars- solution turns from a light blue color and into a green- brick red colour (positive result for sugar). It stays light blue if there is no sugar.

Ethanol test for lipids- turns from colourless solution and into a cloudy emulsion ( positive result of fats) stays colourless if no fats.

Biurets test for proteins- turns from blue and into a lilac purple in the presence of proteins. Stays blue if there is no proteins.

Question 4

What subtrate catalyses the breakdown of starch into maltose molecules?

Answer 4

Amylase or carbohydrase.

Question 5

What subtrate catalyses the breakdown of proteins into amino acids?

Answer 5

Protease

Question 6

What subtrate catalyses the breakdown of lipids into fatty acids and glycerol?

Answer 6

Lipase

Question 7

What is the difference between simple sugars and complex sugars ( complex carbohydrates) ?

Answer 7

Simple sugars- contains one or two sugar units
Gives out immediate energy release

Complex carbohydrates- gives out slow energy release
Contains long chains of sugar units.

Question 8

What does carbohydrates, lipids, proteins contain?

Answer 8

Carbs- carbon, oxygen, hydrogen
Lipids- carbon, oxygen, hydrogen
Protein, carbon, oxygen, hydrogen, nitrogen

Question 9

What is an enzyme?

Answer 9

Is a protein that functions as a biological catalyst which speeds up the rate of a reaction in the body.

Question 10

What is the lock and key theory of enzymes?

Answer 10

Enzymes have a specific unique shape called as the active site. It will bind with a complementary subtrate.

Step 1-
The subtrate is attached to the enzymes active site due to the active site having a complementary shape to the subtrate.
Step 2-
The enzyme catalysts the breakdown of the subtrate
Step 3-
Products are released from the active site.

Question 11

Explain in detail how enzymes speed up reactions in your
body (5 marker)

Answer 11

The enzyme has a unique shape called as the active site. It will BIND with a complementary subtrate like a lock and key.
The enzyme catalyses the breakdown of the subtrate.
Reaction takes place rapidly
Products are released from the active site.
Enzyme then will be ready to catalyze another reaction.

Question 12

Why do enzymes have a specific active site/subtrate?

Answer 12

A chain of amino acids folds to produce a specific shape

Question 13

What factors affect enzymes? And what happens when they affect it?

Answer 13

High Temperatures
PH level

These factors change the enzymes shape, causing it to denature if not controlled

Question 14

Explain why the enzyme activity increases at around 20-30 degrees-

Answer 14

As the temperature increases the molecules gain more kinetic energy causing the enzymes to be able to collide more frequently and so more enzyme- substrate complexes will be formed

Question 15

What happens at high temperatures/ PH levels in enzymes- 4 marker

Answer 15

1- Enzymes are proteins, 2-so the bonds between the amino acids in enzymes will be broken down due to high temperatures/ ph levels. 3-Causing the enzyme to loose its shape. 4-Its active site will no longer be complementary to the subtrate to bind.

Question 16

What is digestion?

Answer 16

The breakdown of large insoluble food molecules into small water double food molecules so that they can be absorbed in the watery blood plasma.

Question 17

Why do digestive enzymes break down big molecules?

Answer 17

Big molecules like carbohydrates (starch), fats, proteins are too big to pass through the walls in the digestive system. So the digestive enzymes break these molecules down into much smaller and soluble molecules so that they’re able to pass through the walls in the digestive system, allowing them to be absorbed in the blood stream.

Question 18

What are the 3 enzymes? and where are they produced? and what do they help breakdown? And where is the breakdown catalyzed?

Answer 18

Protease, amylase, lipase.

Amylase enzymes are produced in the small intestine, salivary glands, pancreas. They catalyse the breakdown of starch into maltose in the salivary glands (mouth) and small intestine.

Protease enzymes are produced in the stomach, small intestine pancreas.
They catalyse the breakdown of proteins into amino acids in the stomach and small intestine.

Lipase enzymes are produced in the small intestine and the pancreas. They catalyse the breakdown of lipids (fats) into fatty acids and glycerol in the small intestine.

Question 19

Where is bile produced?

Answer 19

In the liver

Question 20

Give two functions of bile-

Answer 20

The hydrochloric acid in the stomach makes the ph level too acidic for enzymes to work effectively in, so the bile is an alkaline which produces alkaline conditions for the digestive enzymes to work in since enzymes work best in alkaline conditions.

Bile emulsifies fats, it breaks fats into tiny droplets which gives out a bigger surface area for the digestive enzymes ( lipase) to work faster in digesting fats.

Question 21

What is chyme?

Answer 21

The stomach smashes up food forming a watery paste called as chyme

Question 22

What does the lining of the stomach produce? And what does it contain and how does it help the stomach?

Answer 22

It produces gastric juices.
Gastric juices contain water and also hydrochloric acid which kill microbes that are found in food and it also provides optimum PH for pepsin (an enzyme that breaks down proteins into amino acids)

Question 23

What is the glandular tissue that is found in the stomach?

Answer 23

It is made from cells that Secretes chemicals like hormones and enzymes.

Question 24

What is the epithelial tissue?

Answer 24

Tissue that covers the inside and outside part of the body

Question 25

What is the PH level of the stomach and the small intestine-

Answer 25

Stomach - 2 PH
Small intestine- 7-8 PH

Question 26

How does the pancreas and the liver neutralize the stomach acid?

Answer 26

The liver produces bile salts and the pancreas produces sodium bicarbonate which are both alkali and so neutralize the stomach acid

Question 27

State the adaptations of the small intestines- (5 marker)

Answer 27

The small intestine is very long, it is about 5 meters long in adult humans.
This helps absorption take place since a long intestine gives plenty of time for digestion to be completed, and so all of the foods will be digested.

It has villi, each villius has cells which contain small projections called as the micro villi.
This micro villi helps absorption take place due to it giving the inner surface of the intestine a larger surface area. And so nutrients/foods will be absorbed faster.

Villi walls are thin
This helps absorption take place due to the digested nutrients being able to cross the wall to reach to the blood capillaries and lacteals.

Villi contains a network of blood capillaries
in which they transport glucose and amino acids away from the intestines in the blood and into the liver.

Question 28

Describe two ways how enzymes are used in the industry-

Answer 28

Pre digest baby food
Fruit juice

Question 29

How can enzymes help manufacturers save energy? How can this benefit the environment?

Answer 29

Enzymes allow reactions to take place in the same rate but at lower temperatures.

Less energy is used to run the industrial plant.

Question 30

Give one advantage/ disadvantage of using enzymes-

Answer 30

Adv- enzymes speed up reactions, and enzymes allow reactions to take place at lower temperatures. Which is beneficial to manufactures since they don’t need to spend more money on higher temperatures.

Disadv- enzymes are highly sensitive to surroundings. So if the PH/ temp was changed, it may not work and denature. Which also costs money to control conditions.