Levels of Organization and Organ Systems

The human body is structured into ______. Recall that cells are the smallest units of

life. Cells that are similar in _____ and _______ work together as _____. The human

body has four primary kinds of tissue:

Epithelial tissue –

Connective tissue –

Muscle tissue –

Nervous tissue –

Different types of tissues work together to form _________, which carry out

particular functions. Examples include, ______, ______, ________ and _______.

Organs cannot do all of the necessary work to sustain the body on their own. They must

work together with other organs with related functions (____________) or structures

(_________). This is referred to as an ________________.

The following is a list of the body’s major organ systems and their functions:

Organ System Major Organs Major Function Esophagus, stomach, intestines,

liver, pancreas

Physical and chemical breakdown of food

Heart, blood vessels Transportation of nutrients, gases and

waste; defence against infection

Lungs, trachea, blood vessels Gas exchange

Testes, vas deferens, ovaries,

uterus, fallopian tubes

Sexual reproduction

Kidney, bladder, ureter, urethra Removal of waste

Bones, muscles

Movement of body and body parts

Pancreas, pituitary gland,

adrenal glands

Coordination and chemical regulation of body

activities

Brain, spinal cord, eyes, ears,

nose, tongue, nerves

Response to environment; control of body

activities

What is Nutrition?

Nutritional science is the study of _______ and ______________ found in foods that

affect human _______ and ___________. A thorough understanding about nutrition

enables people to make ___________________. A nutrient is an _____ _______

that is broken down by the body. Good nutrition is important because it:

a) Provides the ________ we need to carry out all of our __________________.

b) Provides us with the essential _____________ that we need as building blocks.

There are three main categories of nutrients:

1. MACRONUTRIENTS (Macromolecules)

Macromolecules are required by the body in _______ amounts. These molecules form

the _________ and carry out the _______ of all cells. They are ________ molecules

that may contain anywhere from _____ to ___________ of carbon atoms. Because of

their _____ and the intricate ______ that macromolecules can assume, these large

molecules are capable of performing a wide variety of complex ______ with great

__________ and __________.

Macromolecules are ___________ of smaller units (__________) linked together.

There are four classes of macromolecules in cells:

i. CARBOHYDRATES (polymers of ___________)

ii. LIPIDS (polymers of _________________)

iii. PROTEINS (polymers of ______________)

iv. NUCLEIC ACIDS (polymers of ________________)

Monomers are linked together by __________ bonds. _________ are responsible for

the __________ and __________ of macromolecules.

2. MICRONUTRIENTS

Micronutrients are needed by the body _______ amounts. There are two main classes

of micronutrients:

i. Mineral - an ________ substance (such as copper, iron, calcium or phosphorous)

that is needed in all body structures in ________ amounts for various

functions, such as the transmission of ___________ and ______

contractions; ___________________________, therefore must be

supplied by _________ or __________________

ii. Vitamin – an ______ molecule that acts as a ______ for essential __________

in the body, such as converting fats and carbohydrates into energy; can

be ______________ or ____________;

____________________________, therefore must be supplied by

______ or ___________

3. Special Nutrient

Water is the considered a special nutrient and is required by all living things. Water is

the most abundant molecule in any cell (constitutes _________ of the human body). It

functions to act as a carrier for ______________ inside (___________) and outside

(___________) of the cell, and as a medium for ________________ (___________).

It also functions as a _____________ between organs, tissues and individual cells.

The following properties of water make life possible, as we know it:

a) Remains ________ over wide range of temp (1C - 99C)

b) _________ most substances involved in living processes such as _______,

__________, _______, __________ and ___

c) Changes temperature gradually (_____________________) when heated

or cooled so it protects cells from rapid temperature changes and therefore

a stable environment

A balanced diet should provide all essential vitamins and minerals. Supplements maybe

required for those who are ill, planning to have children, recovering from injury,

suffering from digestive problems or choose not to eat an optimal diet.

Canada’s Food guide recommends the following daily servings for a balanced diet:

Food Group

Grain Vegetables

and Fruit

Milk Products

or Substitutes

Meat and

Alternatives

Daily Servings

Nutritional information about the food you are eating is found on most packaging:

a) Specific amount of food

All the information in the Nutrition Facts table is based on a specific amount of food.

The specific amount may be indicated by a phrase such as: a slice, one egg, two cookies,

followed by the metric measure (grams, cups, millilitre etc…)

b) % Daily Value

The % Daily Value provides a quick overview of the nutrient profile of the food, allowing

product comparisons based on more than one nutrient. It puts nutrients on the same

scale (0% - 100% Daily Value). You can quickly identify the strengths and weaknesses of

a food product.

c) Calories

Calories are an expression about the amount of _____ a food provides. One calorie is

measured by the amount of energy it takes to raise ___ of water by ____________.

Foods that provide energy and no other nutrients are called

_______________________.

d) Nutrient claims

The Government has rules in place

that must be met before a

nutrition claim can be made on a

label. Examples of nutritional

claims include:

Functional foods - those that

provide more for your body than

just essential nutrients. These

benefits include strengthening the

immune system, slowing the ageing process, aid digestion

(________________________)

Whole foods - contain a natural level of a functional component

(__________________)

Fortified foods - contain added ingredients

(________________________________)

Enhanced foods - contain a functional component that has been introduced into the

organism from which the food comes – through breeding, feeding or genetic engineering

(__________ ____________)

e) List of ingredients

The list of ingredients is mandatory and has been on the food product package for many

years. All of the ingredients for a food are listed in descending order by ________.

The ingredients present in the greatest amount in a product are listed first. The list is

also a source of information for people who want to avoid certain ingredients or verify

the presence of an ingredient in a food.

Macromolecules Carbohydrates A green plants ability to get energy from the Sun and turn CO2 from the air into _____

(carbohydrates) is called ___________ and is represented by the chemical equation

below:

Therefore, all carbohydrates come from green plants. Carbohydrates are nutrients

based on molecules of sugar; because of this they are called “___________” which

means “_____”. All carbohydrates have the general formula C-H2O, in other words they

are “carbon-hydrates”. The function of carbohydrates are to act as the

_____________________ in cells as they pass through the process of ________

______________, which is represented by the chemical equation below:

In photosynthesis _________ is used to produce ______ molecules (glucose). In

cellular respiration the ____ molecule (glucose) is broken down and releases _____ (in

the form of ATP) for the cell to use.

Two important organelles are specialized for energy conversion.

1. ___________ (sites for cellular respiration)

2. ___________ (sites for photosynthesis)

After plants produce glucose they can convert it

into a variety of other sugar molecules by

altering their shape or by bonding them together.

The two main varieties of carbohydrates that we

consume are _______________ such as

________________ (glucose and fructose) or

_______________ (sucrose and lactose), and

polysaccharides or ____________________

(________ – ________ of sugar in ______).

Simple sugars tend to provided ___________

energy supplies whereas complex carbs a more

______________ source of energy.

Fibre is a carbohydrate (_________) found

in the _________ of plants, that cannot be

_______ by humans. It helps to hold _____

and provide ______ in the large intestine,

thus it helps to eliminate our waste.

Current North American guidelines recommend that carbohydrates, especially

_________ carbohydrates provide ____ to ____ of your daily energy requirements,

which should be approximately ____________.

Healthy carbohydrates such as those

provided from ___________, ______

and __________ are excellent dietary

sources of carbohydrates. When your

diet is rich in these carbohydrates, your

body extracts energy from them, saving

_________ for muscle building and

body repair.

Whole grains are those that include all portions of the grain. Processed grains have had

the _____ and the _____ portion removed. These areas provide a number of essential

__________ and _________ along with some healthy _______ and ________.

Carbohydrates are processed to alter their ________ and to extend their

___________.

Unhealthy sources of carbohydrates include white bread and

pasta, candy, pasteries, soda and any other highly processed

or refined foods. These carbs may contribute to weight gain,

interfere with weight loss and promote diabetes and heart

disease.

__________ is a carbohydrate that acts as a storehouse

for ____________ in humans and ________. It is

produced in the _______. Excess consumption of

carbohydrates can get converted into ________ (a

__________ energy __________ molecule) and may lead

to an increase in ___________ production.

_________ disease in an autoimmune response to ________, a collection of proteins

found in grain products.

Lipids

Fats serve as a ____________________ along with providing _______, acting as

________ and the main component of _____________. Current guidelines

recommend that dietary fats should supply no more than _____ of your daily energy

requirements. There are two main types of fat we consume, _______________ and

________________.

Triglycerides are composed of a __________ molecule attached to _____________

chains. The fatty acid chains determines the type of triglyceride. The ______ and

_______ can vary from one fatty acid to another.

A) Saturated Fatty Acids

There are only single bonds between each carbon atom. This organization allows for a

______ arrangement of the fatty acid tails, allowing them to ____ close together,

which explains why saturated fatty acids are ________ at room temperature.

These are found in foods such as ______, ____, ______

and ______. In the past, saturated fats have been closely

associated with ______________. More recent evidence

suggests that there are other factors to consider when

looking at the impact of saturated fats. As a guide,

saturated fats should NOT be considered a healthy fat, but

if less than ____ of your daily calorie requirements is in

the form of saturated fat it will have little impact on risk

of cardiovascular disease.

B) Unsaturated Fatty Acids

There is one (_______________) or more (___________) ______ bonds in the

carbon chain. This means that not every carbon is bonded to its maximum number of

hydrogen atoms. Double bonds produce _______ in the fatty acid chain, consequently,

the more double bonds the chain possess, the greater the difficulty for these chains to

pack together. This explains why unsaturated fats form ____ at room temperature

(___). These are found in foods such as __ – olive, corn, sunflower etc…

______________ or ___________.

Most naturally occurring unsaturated fatty acids are found in what is called the _____-

configuration. These types of fats appear to ________ total cholesterol levels.

Unsaturated fats can have their double bonds

chemically ___________ with hydrogen atoms (a

process termed ____________). During this process

______ fats are produced. The resulting molecule

creates __________ chains, which are capable of being

_________ at room temperature, such as _________.

Trans-fats elevate _____ (bad) cholesterol levels and

lowers _____ (good) cholesterol levels.

Omega-__ and omega-__ fatty acids are essential

fats found mainly in ________. Omega fats are

required to build _______, the protective covering

around ______ of our ________ cells.

There are two types of cholesterol; about _____ of cholesterol is made by our ______,

while the other _____ comes from _______:

1. Dietary Cholesterol

Found in foods containing animal fat -

____________________________

____________________________

Doesn’t normally cause blood cholesterol

to ___________ in most people

2. Blood Cholesterol

Most of this cholesterol is produced by the _______ from the triglycerides

consumed

Two types - HDL and LDL

HDL (good) - High-Density Lipoprotein

Helps ___________________ from body

To boost HDL - ___________, be ___________ and maintain

_________________

LDL (bad) - Low-Density Lipoprotein

Clogs arteries because these are deposited on artery walls (_______), blocks

circulation, increases risk __________________ or ___________

To lower LDL - cut down on ________ and _____ fats, eat more foods containing

soluble _________

Proteins

Accounts for ___ of the dry weight of cells

Wide variety of __________ in organisms –

________________________________ etc…

Huge variety of __________ – ___________,

_________________ etc…

Each protein has a unique _________________

__________

Always assembled from a common cellular pool of __________________

__ of the 20 amino acids are considered _______ amino acids as they cannot be

produced by the body, but must be obtained through ________

Proteins should make-up ____________ of daily energy requirements (more if

doing weight training)

Animals sources such as ____________________ and ____ are sources of

_________ proteins (provide all 8 of the essential amino acids)

__________________ and __________ are _________ proteins, because

they do not provide all the essential amino acids

Vegetarians attempt to avoid all meat products, although may consume dairy and

egg products. Vegans will restrict their diet to foods derived from plants

Vegetarians and vegans must carefully balance their food intake in order to

obtain all eight essential amino acids

An amino acid is composed of a _____ atom (called the _____ carbon) __________

bonded to four different groups:

Amine group (NH2)

Carboxyl group

Hydrogen atom

Side chain shown as “R-group”

(different for all 20 amino acids)

Types of Digestion All organisms must have some way of obtaining essential ________ needed to make

their own structures and to perform life functions. Organisms that depend on organic

molecules manufactured by other living things are called _____________.

Digestion can occur _________ or _________. External digestion is thought to be the

first type of system to evolve and organisms such as _______ and _______ still rely on

it today. In this process, enzymes are ________ into the environment surrounding the

organism, where they break down organic material and then some of the products

____________ (move from an area of _____ concentration to ____ concentration)

back to the organism.

Internal digestion evolved later, where animals make use of a ______ system to digests

organic material ______ of their body. This method is more efficient as it allows

organisms to _______ and _______ their food and _______ and _______ the

environments more effectively for the digestive process.

Digestion can also be considered as ___________ or ___________. Intracellular

digestion is the type of digestion in which food particles are taken ____________ and

subjected to the action of enzymes there. Extracellular digestion is the digestion of

food occurring ______________________________ (as in the tube arrangement

common in animals).

Types of Digestive Systems There are three main types of digestive systems:

1.

2.

3.

All of these systems follow the same four steps:

Ingestion –

Physical and Chemical –

Breakdown

Absorption –

Egestion –

1. Vacuole System

Food is digested inside a vacuole formed within the cell.

Examples: _______________ and ___________

2. Closed Tube System

This type of digestive system consists of a “__________”

structure with only ______________. Both ingestion and

excretion occur through the same opening.

In the digestive cavity, food is partially broken down by

enzyme action and absorbed into cells lining the inside of

the "bag". These cells complete the digestion process.

Example: _____________ and a _____________

3. Open Tube System

This type of digestive system consists of a tube with ____

openings. One opening is used to ingest food particles and

the other is used to excrete waste. Examples: ________

and ___________. Open tube systems usually require:

1.

2.

Ingestion

Digestion is a complex process, which results in food being broken down

into its component molecules. It involves:

1) Mechanical (Physical) Digestion

2) Chemical Digestion

In humans, the digestion process takes about ______ hours and requires passage through an extremely long tube system (_________________), separated into distinct regions that perform specific functions.

Section Length

The Mouth and Pharynx

Both physical breakdown and chemical digestion occur in the mouth. The

______ and _______ are important for ______ digestion and the

______________ for ___________ digestion.

Inside of your mouth, covering the surface of your tongue are tiny

projections called _________, and every one holds hundreds of

_____________.

Taste is closely linked to _______ (smell); much of what we call the taste

of food is actually the _________. Taste is a combination of sensations –

______, ______, ______ and ______.

One theory is that taste buds for the different sensations are clustered in

specific regions on the surface of the tongue. Can you figure out where

these clusters are located?

Sweet Sour Salty Bitter

Human teeth

Each tooth has two divisions, the ____ and

an ___________. Enamel, which is formed

of _______compounds, is the _________

substance in the body.

Type of Tooth Number Function

Incisor

Canine

Premolars

Molars

Wisdom

A) How Chewing Helps Digestion?

Sugar Appearance Before Appearance After

Loose

Cube

B) How did the surface area of the types of sugar compare?

C) How does surface area affect the rate of dissolving?

Chemical digestion begins as food is chewed, and it begins to mix with

_______ produced by the three salivary glands – ______, _______ and

____________.

Some functions of saliva include:

It wets and __________ so food can be swallowed easier and begins

the _________ process (required for _______ and

_____________)

It causes the food particles to stick together

to form a food mass, or _______

It contains a digestive enzyme called ______

(or ________________), which breaks down

starch into simple carbohydrates

The tongue pushes the food ____ to the back of

the throat, and against the _______________,

which initiates the automatic __________ reflex.

The _________ prevents ____ and _______ from

entering the ______ during swallowing, while the

______ stops food from entering the ________ cavity.

The Esophagus

No digestion, neither ______ nor _______ occurs in the esophagus. It

secretes ________, a lubricant which aids the bolus of food in its journey

to the stomach.

The movement of food down the digestive tube is aided by

_____________.

Peristalsis consists of alternate waves of

_________ and __________ in the

muscular walls of the alimentary canal.

Where the esophagus opens into the

stomach, there is a ring of muscle called a

__________.

The ________________ acts as a valve

and controls the passage of food from the

__________ into the ___________.

__________ or acid indigestion occurs

when ____________ backs up into the

esophagus, _______ its lining. Pain is felt

in the region of the _____ where the

esophagus is located, but the condition has

nothing to do with the heart.

The movement of food out of the stomach,

up the esophagus and out the mouth is called _________________.

The Stomach and Intestines

Through the digestive process, macromolecules are broken down into molecules small enough to

be ________________ from the intestine and transported to ___________ cells:

Carbohydrates

Proteins

Lipids (triglycerides)

_________ is the main process in which food is chemically broken down. During hydrolysis, a

water molecule is added at the point where a _____ occurs between __________. Hydrolysis

occurs at a very slow rate, but is immediately sped-up by ________ (biological catalysts made

of _____________).

Enzymes are formed by _________ cells, which can exist _____, in ________ or in ______. A

gland is a structure made up of a complex system of tubules connected to other areas by

_______. Enzymes are very _____ and will only catalyze specific ________. Many enzymes

require the presence of _________ or __________ in order to function properly.

The Stomach

The stomach is the site for temporarily storage of

______ and initial ______ digestion. Both ______

breakdown and _________ digestion occurs here.

Physically the stomach has a ________ appearance

and can hold up to ______ of food.

The stomach has ______ or ______ that allow it to

expand and contract. When your stomach is _____,

your ______________ produces a hormone called

_______ that travels to your brain to tell you that

you are hungry. When your stomach is full

(___________) the hormone _______ is produced

by __________ (fat) tissue to signal your brain

that you are full.

Food in the stomach is broken down mechanically into smaller particles by the ___________ of

the ____________ stomach walls (_______ muscles). This is referred to as _________.

The food mass is broken down chemically as it is churned and mixed with __________ juice

secreted by two types of glands:

1. Pyloric glands

Secrete __________, which covers the stomach lining and __________ it.

2. Gastric glands

Secrete very _____ gastric juice, which has a pH of ___ to ___. Gastric juice

contains hydrochloric acid (_____) and the digestive enzyme ____________.

When pepsinogen is converted to its active form of _______, the breakdown of

_______ into their individual _______________ begins. HCl helps the

breakdown of ____ macromolecules.

There are three mechanisms involved in stimulating the flow of gastric juice:

1. The _______________, or _______ of food stimulates the ______ to send messages via

nerve impulses to the _______________.

2. Food ____________ the __________ of the stomach.

3. Secretion of the hormone _______ caused by _______ of the _____________. Gastrin

stimulates production of large amounts of ____________.

In a typical day __ litres of fluid pass through the lumen of an adult’s gastrointestinal tract.

Only about __ litres of that volume enters through the ______. The remaining __ litres come

from body _____________ secreted along with __________ and _____________.

A common disorder associated with the stomach occurs following the destruction of the cells

_____ in the stomach. This leads to a _________. Until recently, diet and stress were always

thought to be the leading cause of ulcer formation. Scientists have now discovered a remarkable

organism, _____________________, which thrive in the stomach’s formidable environment

and are believed to cause most cases of ulcers.

The Small Intestine

Most ______________ and almost __________ of nutrients occur here. After food leaves

the stomach, regulated by the ____________, it enters the first part of the small intestine

called the ________. At this stage, the partially digested food is called ____. The presence of

chyme in the small intestine, stimulates secretion of the hormone _____________ and

___________________. When these hormones reach the pancreas and liver they stimulate

the production of ___________________ and _______.

The small intestine itself produces a number of enzymes that continue the chemical digestion

process, such as:

Secretes ____________ which completes the breakdown of ____________ (________)

Secretes ____________ which complete the breakdown of __________

Secretes __________ which breaks down __________

The Pancreas

Produces ______________________ which _____________ stomach acid

Secretes the digestive enzymes _____ (______), _______ (___________) and ______

(__________)

Produces __________ and __________ in response to ____________________

Insulin makes _____________ more _______ to _________ and _________________ to

_________ blood sugar levels

Glucagon ______ blood sugar levels by stimulating the breakdown of _______ in the ____

Insufficient insulin production can lead to _____________

The Liver Produces _____ – an ___________ agent needed for the physical digestion of ______

Bile is stored in the ________________

Storage of _____________ (___________)

Production and storage of ____________ (A, D, E and K)

Process _______ – triglycerides, cholesterol

_______________ many harmful substances (___________)

Excessive damage to liver tissue can lead to the development of ___________; a condition

called _____________

Peristaltic contraction continue throughout the intestines which has 3 main effects:

1. They _______________ chyme through the intestine moving the bolus along

2. They __ the chyme with digestive enzymes and break down food particles mechanically

3. Bring the intestinal contents into contact with the intestinal wall speeding _________

During absorption, digested nutrients pass through ___________ and enter ___________ or

__________ in structures called _______.

The capillaries act to absorb __________, ________, ________ etc… into the __________

system. Lacteals are

part of the ________

_________ and absorb

________ and ______

into tiny vessels.

The small intestine has

a number of structural

features that increase

its surface area for

maximum absorption of

nutrients:

1. The small intestine is very ________

2. Its lining has many ______

3. The lining is covered with millions of ______________ called ______, which increase

the ______________ by as much as ____ times

4. The epithelial cells of the villi that face into the intestinal opening have tiny projections

called _____________ that further increase the surface area

______ disease is an ___________ disorder of the small intestine that occurs because of a

reaction to _____ which is found in ______ products. Exposure to gluten causes the ____ of

the small intestine to _______. This interferes with the _________ of nutrients and water

causing ___________ and ___________.

_________ disease is a chronic ____________ disease of the intestines, primarily caused by

______ in the small and large intestines, but can affect the digestive system anywhere between

the ______ and the _______.

The Large Intestine

_________ and __________ materials pass from the small intestine into the large intestine.

No digestion occurs in this portion of the digestive system.

Functions of the large intestine include:

1. Reabsorption of ______ from the food mass

2. Absorption of vitamins __ and __ produced by live __________ in the large intestine

3. Elimination of undigested and indigestible material from the digestive tract (_______)

Examples: _______ from plant cell walls, large quantities of ___________________ and

______________ from the digestive tract

Fecal matter is stored in the last part of the large intestine, the ________, and periodically

eliminated, or ____________, through the __________.