1. Digestion and Nutrition

2. What is metabolism? Why cant we say all living things “eat”?
Tuesday, March 31
What is metabolism? Why cant we say all living things “eat”?
OBJ: Understand animal nutriton.

3. Why can humans survive weeks without eating a meal?
Wednesday, April 1
Why can humans survive weeks without eating a meal?
OBJ: Understand animal nutrition.

4. Thursday, April 2
Explain why researchers suggest eating a meal when taking some vitamins and not having to eat when taking others?
OBJ: Understand animal nutrition.

5. METABOLISM
The set of life-sustaining chemical transformations within the cells of living organisms. These enzyme- catalyzed reactions allow organisms to grow and reproduce, maintain their structures, and respond to their environments.

6. The Need to Feed
All animals eat other organisms—dead or alive, whole or by the piece (including parasites).
In general, animals fit into one of three dietary categories.
Herbivores, such as gorillas, cows, hares, and many snails, eat mainly autotrophs (plants and algae).
Omnivores, such as cockroaches, bears, raccoons, and humans, consume animal and plant or algal matter.
Carnivores, such as sharks, hawks, spiders, and snakes, eat other animals.
Humans evolved as hunters, scavengers, and gatherers.

7. Homeostatic mechanisms manage an animal’s energy budget
The flow of food energy into and out of an animal can be viewed as a “budget,” with the production of ATP accounting for the largest fraction by far of the energy budget of most animals.
ATP powers basal or resting metabolism, as well as activity and, in endothermic animals, thermoregulation.
Nearly all ATP generation is based on the oxidation of organic fuel molecules—carbohydrates, proteins, and fats—in cellular respiration.

8. The monomers of any of these substances can be used as fuel
Fats are especially rich in energy, liberating about twice the energy liberated from an equal amount of carbohydrate or protein during oxidation.
When an animal takes in more calories than it needs to produce ATP, the excess can be used for biosynthesis.
This biosynthesis can be used to grow in size or for reproduction, or it can be stored in energy depots.
In humans, the liver and muscle cells store energy as glycogen, a polymer made up of many glucose units.
This is FAT!

9. On average, how long can humans survive without eating (starvation)?
Question?
On average, how long can humans survive without eating (starvation)?

10. FAT IS OUR FRIEND! (Sometimes…)
WEEKS!!!!
FAT IS OUR FRIEND! (Sometimes…)
The human body expends liver glycogen first and then draws on muscle glycogen and fat.

11. Energy Budget Balance
Three conditions can exist for organisms if energy balance is not being maintained:
Undernourishment: diet of a person or other animal is chronically deficient in calories (ie. not having enough food)
Overnourishment: “obesity”, the result of excessive food intake
Malnourishment: diet is missing one or more essential nutrients

12. The main stages of food processing are ingestion, digestion, absorption, and elimination
Ingestion, the act of eating, is only the first stage of food processing
Digestion, the second stage of food processing, is the process of breaking food down into molecules small enough for the body to absorb.
Absorption: nutrients are absorbed into the bloodstream from the small intestine
Elimination: Excretion of waste product from the digestive system through the large intestine out through the anus (defecation)

13. Tracing the Path of Food
On your handout of the digestion system you are going to trace the path of food (choose what you are eating! :) )
Use pages in your book!
Include information about what is happening at each stage
Organs and glands involved
How is food being changed throughout
Muscle involvement
Hormone involvement
Enzymatic Activity at each stage

14. Nutrition
To be sure that the essential nutrients are included in the diet, it is necessary to eat a balanced diet

16. Dietary Essentials
Vitamins are organic molecules required in the diet in quantities that are quite small compared with the relatively large quantities of essential amino acids and fatty acids animals need
So far, 13 vitamins essential to humans have been identified.
These can be grouped into water-soluble vitamins and fat-soluble vitamins, with extremely diverse physiological functions.

17. Fat-Soluble vs. Water Soluble
The water-soluble vitamins include the B complex, which consists of several compounds that function as coenzymes in key metabolic processes
Vitamin C, also water soluble, is required for the production of connective tissue.
Excessive amounts of water-soluble vitamins are excreted in urine, and moderate overdoses are probably harmless.
The fat-soluble vitamins are A, D, E, and K.
They have a wide variety of functions.
Excess amounts of fat-soluble vitamins are not excreted but are deposited in body fat.
Overconsumption may lead to toxic accumulations of these compounds

18. Minerals
Minerals are simple inorganic nutrients, usually required in small amounts—from less than 1 mg to about 2,500 mg per day.
Humans and other vertebrates require relatively large quantities of calcium and phosphorus for the construction and maintenance of bone.
Iron is a component of the cytochromes that function in cellular respiration and of hemoglobin, the oxygen-binding protein of red blood cells.
Magnesium, iron, zinc, copper, manganese, selenium, and molybdenum are cofactors built into the structure of certain enzymes.
Sodium, potassium, and chloride are important in nerve function and have a major influence on the osmotic balance between cells and the interstitial fluids.

19. Adaptation to Diet
Depending on the animals dietary needs, the more simple or complex the digestive system will be
Dentition (morphology and arrangement of teeth in animals) differs according to modes of nutrition
4 Different Teeth Types:
Incisors: used for shearing
Canines: used for tearing
Premolars: used for grinding
Molars: used for crushing

20. Dentition Images
For each of the three organisms, color in each tooth type they have
Explain why that organism has that particular dentition type (Hint: what type of dietary category do they fall into?)
Do you think the dietary system of that organism is simple or complex? (Hint: Think of the foods each organism consumes)