1. Animals: Structure & Function
Unit 4
Animals: Structure & Function

2. Learning Goal
To learn more about the different macromolecules found in food sources and how they are broken down
To investigate the roles of minerals and vitamins in the body
To learn more about the 4 stages of food processing

3. Section 10.1
Function of Digestion

4. Introduction What I already Know about the Digestive System
What I want to know more about
What I learned about the Digestive System

5. Distribution of body fluids
Living on a planet that is made up of mostly water, it is no surprise that WE are also made up of mostly water

6. Distribution of body fluids
As you can see, based on the different compartments of fluid in the body, we are made up of 60% water
And a few other things

7. Distribution of body fluids
Water in the body is divided into 3 compartments:
Cytoplasm inside the cells
The fluid between the cells called interstitial fluid
And fluid in the blood

8. Distribution of body fluids
These compartments are also made up of 1000s of different kinds of molecules and ions, like:
water, phosphates, hydrogen ions, and sodium ions
These are inorganic (non-living) matter

9. Distribution of body fluids
Other molecules, called organic molecules, are made up of hydrocarbons (hydrogen & carbons), and other atoms like oxygen, sulfur, and nitrogen
Larger, more complex organic molecules, called macromolecules, are make up the nutrients we know as lipids, carbohydrates, proteins, & nucleic acids
These nutrients are the raw materials that our bodies need to provide energy, to regulate cellular activities, and to build and repair tissues

10. Macromolecules
Defined as: very large molecule made up of smaller molecules that are linked together
Energy can be released from these macromolecules inside the body through our metabolism and cellular pathways
These 4 macromolecules are ESSENTIAL to our existence, thus called essential nutrients

11. Macromolecules – pg. 403 Macromolecule Main Function Examples
Carbohydrates
Provide materials to build cell membranes
Provide quick ENERGY for cells
Lipids
Store energy to be used later
Cushion / insulate organs
Make up cell membranes
Proteins
Provide structure in blood cells, tissues, and muscles
Make enzymes that help speed up reactions in cells
Provide immunity against infections Transport ions in cells
Nucleic Acids
Contain all human genetic information
Direct how an organism grows
Coordinate the production of proteins

12. Carbohydrates Carb’s are made up of three elements:
1. Carbon Hydrogen 3. Oxygen
These molecules usually provide quick energy to the body (made by photosynthesis, broken down by respiration)
Important role in:
Energy Metabolism
Storage
Cell structures

13. Carbohydrates There are 2 main types of carbohydrates : Simple Sugars:
Monosaccharides
Complex Sugars:
Polysaccharides
“Mono” = one
“Saccharide” = Sugar
Are carbohydrates made up of small rings of carbon, hydrogen, and oxygen
Include: glucose, fructose, galactose
“Poly” = many
Are carbohydrates made up of large rings of carbon, hydrogen, and oxygen
Include: glycogen, starch, and cellulose

14. Lipids
Lipids are hydrophobic (water hating) molecules made up of Carbon, Hydrogen, and Oxygen
They contain fewer polar O-H bonds than and more non polar C-H bonds than carbs
Thus, they are insoluble in water but soluble in other nonpolar substances
This is why water and oil do NOT mix
This is an important property of cell membranes and help control what things can come in and out of our cells

15. Lipids Tri = Three They contain 3 Fatty Acids & 1 Glycerol Molecule
The basic structure of a lipid is a molecule of glycerol attached to fatty acid chains, in the form of a Triglyceride
Tri = Three
They contain 3 Fatty Acids & 1 Glycerol Molecule

16. Lipids
Lipids store LOTS of energy in the body, but are mainly found in the form of phospholipids within our cell membranes

17. Proteins
Are made up of smaller sub-units (like Lego) of molecules called Amino Acids
Most proteins are made up of 100s of amino acids joined together by a peptide bond into larger chains called polypeptides
Proteins help build and repair muscles and cell membranes

18. Nucleic Acids
Are responsible for directing the growth and development of all organic organisms using a special chemical code that is found in our genes
The information is stored in our DNA, which helps us to not only control what happens in the body, but also make proteins using RNA
The 2 types of Nucleic Acid are
DNA – deoxyribonucleic acid
RNA – ribonucleic acid

19. Braking down Macromolecules
In order to use the nutrients of carbohydrates, lipids, and proteins taken in from food
These Large Macromolecules have to be chemically broken down into smaller molecules in order to enter cells within the digestive system
This is done through a reaction that adds water to the bonds in large macromolecules, called Hydrolysis
Where the adding of H2O brakes large chains into smaller pieces

20. Braking down Macromolecules
Sometimes the breakdown of a large macromolecule needs more help than just water
In this case, they would use ENZYMES to help speed up how fast these molecules are broken down
Read pg. 404 and give examples of enzymes used in the digestive tract / where they are found:
Macromolecule
Type of Enzyme Used / Where
Carbohydrate
Lipid
Protein
Nucleic Acid

21. Braking down Macromolecules

22. Roles of Vitamins & Minerals
In addition to macromolecules, we need certain amounts of vitamins and minerals in our bodies in order to function
Vitamins and Minerals are both organic and inorganic substances that help chemical reactions to take place in our body (like a neuron firing or our hearts beating)
They also assist tissue development, growth, and immunity over time

24. Role of Water in the Body
You already know that we are made up of lots of water, thus – it is has IMPORTANT roles in the body:
Transporting dissolved nutrients into cells of the small intestine (SI)
Flushing out toxins from cells
Lubricating tissues and joints
Forming essential body fluids (blood / mucus)
Regulate body temperature (sweating if too hot)
Eliminating waste through urinary system / sweat

25. How Animals get their Food
Animals are heterotrophs – which means they cannot make their own food, and need to eat something from their environment in order to live
Regardless of their size, shape, and food preferences, ALL ANIMALS get their food through 1 of 4 ways via a Feeding Mechanism

26. Use pg. 407 to complete the table
Feeding Mechanism
Description
Example
Filter Feeders
Substrate Feeders
Fluid Feeders
Bulk Feeders

27. 4 stages of Food Processing
When an animal initially get food, it is not in a form that the body can use
So it must DIGEST it in order to get the most nutrition out of it, where
The digestive system breaks down food into useful substances that can be absorbed into the circulatory system through microvilli that line the small intestine of the digestive tract
All of this takes place in 4 important steps

28. 4 stages of Food Processing
4. Elimination
The REMOVAL of undigested food that was not needed was solid waste from the body
3. Absorption
The TRANSPORT of products from digestive phase into the circulatory system, which then send nutrients to the rest of the body – where needed
2. Digestion
The BREAKDOWN of food mechanically and chemically processes into molecules small enough for cells in the body to take in and use properly
1. Ingestion
The taking IN or EATING of food

29. Digestion & the Alimentary Canal
To digest their food, most animals have a digestive tract that consists of a long open tube
This tube is called the alimentary canal
where it has a mouth at one end to take in food, and a anus at the other end to eliminate waste
As food moves through this tube, different organs of the digestive system process the food in different ways

30. Digestion & the Alimentary Canal

31. Alimentary Canal Example – Earth Worm:
Food enters the mouth and passes into
The Pharynx (throat) and into
The Esophagus, who channels the food into
The Crop (stomach 1), where food is softened & stored
The muscular Gizzard (stomach 2) churns & grinds food
And then the food is further digested into the intestine

32. Digestion & the Alimentary Canal
In more complex animals, food enters the mouth and is physically broken apart into smaller pieces by teeth
Food is then broken down further as it moves along the digestive tract by the muscular contractions of the tube itself
This process of PHYSICALLY breaking down food into smaller pieces = Mechanical Digestion

33. Digestion & the Alimentary Canal
At the same time, many fluid-releasing glands in the mouth and further along the digestive tract add LIQUID and ENZYMES that help break down macromolecules (carbs, protein, lipids) into smaller molecules
The adding of Enzymes / Liquids from glands to help digestion = CHEMICAL DIGESTIONS

34. Digestion & the Alimentary Canal

35. Human Digestive Tract