Download Chapter 5 Nutrients at Work

NUTRIENTS AT
WORK
Chapter 5
Objective
◦ Explain the impact of nutrients on your body and health.
◦ Describe standards and guidelines that provide information
about nutrient requirements.
◦ Summarize the steps in the digestive process.
◦ Explain how nutrients are absorbed, transported, and stored
in the body.
◦ Discuss the role of metabolism in the body.
Terms
◦ Absorption
◦ Esophagus
◦ Adequate intakes (AI)
◦ Glucose
◦ Anemia
◦ Glycogen
◦ Basal Metabolism
◦ Malnutrition
◦ Calorie
◦ Metabolism
◦ Chyme
◦ Oxidation
◦ Dietary Reference Intakes (DRI)
◦ Pancreas
◦ Digestion
◦ Peristalsis
◦ Enzyme
◦ Recommended Dietary Allowances (RDA)
◦ Villi
6 Basic Nutrients and Their Functions
◦ Carbohydrates – Provide the body’s main source of energy.
◦ Fats – Provide a concentrated source of stored energy as well as
insulation for the body.
◦ Proteins – Help build, repair, and maintain body tissues.
◦ Vitamins – Help regulate many vital processes.
◦ Minerals – Help the body work properly.
◦ Water – Participates in chemical reaction in the body and helps
transport materials to and from cells.
Nutrients and Health
◦ Malnutrition – a deficiency or severe shortage of a nutrient, or having too much of a nutrient from
overeating.
◦ Anemia – not getting the recommended amount of iron.
◦ Having a healthy lifestyle helps with:
◦ Appearance
◦ Fitness
◦ Weight
◦ Illness
◦ Healing
◦ Emotions
◦ Future Health
Digestion
◦ Digestion – is the mechanical and chemical process that breaks food down to release nutrients in forms your
body can absorb.
◦ Parts of the digestive system:
◦ Mouth
◦ Salivary Glands
◦ Esophagus
◦ Stomach
◦ Liver
◦ Pancreas
◦ Small Intestine
◦ Large Intestine
The Mouth
◦ Digestion begins by chewing food to the consistency of applesauce.
◦ Saliva is released in the mouth containing enzymes that help to break down food.
◦ The sight and smell of food helps to release the saliva and gets your mouth “watering”
◦ Taste buds on the tongue can identify four general flavors:
◦ Salty
◦ Bitter
◦ Sour
◦ Sweet
The Esophagus
◦Connects the mouth to the stomach.
◦Once food is chewed it passes into the esophagus.
◦Food moves through the esophagus by peristalsis to
the stomach
The Stomach
◦ Hollow, muscular pouch at the end of the esophagus, below the rib cage.
◦ Widest part of the digestive system, and can hold about 6 cups of food.
◦ Produces gastric juices (acids and enzymes) that helps food break down chemically.
◦ Also breaks down food mechanically through peristalsis.
◦ Turns food into a thick liquid called chyme.
The Small Intestines
◦ Attached to the stomach. Food passes from the stomach to the small intestines.
◦ Three types of digestive juices act on the chyme as the breakdown of carbohydrates,
proteins, and fats continues.
◦ Bile – Helps the body digest and absorb fats. Bile is produced in the liver and
stored in the gall bladder.
◦ Pancreatic juice – contains enzymes that help break down carbohydrates, proteins,
and fats. The Pancreas produces this substance.
◦ Intestinal juice – works with other juices to break down food. It is produced in the
small intestine.
Absorption of Nutrients
◦ Once food is broken down it must be absorbed into the
bloodstream.
◦ This takes place through the surface of the small intestine.
◦ Villi (billions of tiny, fingerlike projections) increase the
surface area of the intestine so that more nutrients can be
absorbed.
◦ After absorption, waste material is moved into the large
intestine.
Nutrient Transportation
◦ After nutrients are absorbed they are transported to the liver to be
turned into forms that the body can use.
◦ Carbohydrates are broken down into glucose a simple sugar that is
the body’s basic fuel.
◦ Fats are broken down into fatty acids.
◦ Proteins are broken down into amino acids.
◦ Vitamins, minerals, and water are not broken down.
◦ After any necessary breakdown, nutrients are ready to be transported
in the bloodstream to individual cells.
Nutrient Storage
◦ If not immediately needed, some nutrients are stored for further use.
◦ Liver turns glucose into glycogen, the extra is turned into fat.
◦ Fatty acids and amino acids are converted into body fat and
deposited throughout the body.
◦ Minerals and vitamins are stored in various ways.
◦ Vitamins that are dissolved in fat are stored in the liver.
◦ Vitamins that are dissolved in water are removed from the body.
Metabolism
◦ Metabolism – living cells use nutrients in many chemical reactions that
provide energy for vital processes and activities.
◦ Oxidation – glucose in the cells combine chemically with oxygen to
produce energy and heat.
◦ Calorie – amount of energy needed to raise the temperature of 1
kilogram of water 1 degree Celsius.
Recommended Requirements
Calories in Nutrients
Nutrient
Calories
1 g pure
Carbohydrate 4 Calories
1 g Pure
Protein
4 Calories
1 g Pure Fat
9 Calories
Recommended Calorie Amounts
Category
Calories
Teen males, many active
men, and some very active
women.
2,800
Older children, teen
females, active women, and
most emn. Women who are
pregnant or breast-feeding
may need more.
2,200
Younger children, women,
and most older adults
1,600
Nutrient Sources for Calories
Nutrient
Teens
Adults
Carbohydrate 45-65% 45-65%
Proteins
10-30% 10-35%
Fats
25-35% 20-35%
Metabolism
◦Basal metabolism – the minimum amount of energy
you need to maintain basic functions.
◦Energy requirements – the number of calories you
need for energy on a given day. Age, weight, gender,
and activity level do impact what you need.