Nutrition

What is one of the most important characteristics of life??

Let’s dig deeper

• Read and jot some notes for the following pages:*Page 784 (Bioenergetics of animals)-785 (end of page)*Page 788 (Regulating Internal Environment—using Figure 40.10)*Pages 792-796

Bioenergetics of an Animal(Pages 784-785)

• Eat organic molecules synthesized by other organisms→enzymatic hydrolysis for digestion →molecules containing energy are absorbed by body →cells obtain chemical energy from ATP via cellular respiration and fermentation →work can be done to sustain life

• THAT’S OBVIOUS…tell us something we don’t already know!!!!!!

Figure 40.7

• What does this tell us?

• How do we use ATP?• What is biosynthesis?• How do we give back

to the environment?• What are carbon

skeletons that lead to biosynthesis?

Carbon Skeletons

•CHONPS!!!!!!!!!

Metabolic Rate

• Amount of energy (calories or kilocalories) an animal uses in a unit of time

• Calorie=kilocalorie• Tricky nutritionists, very

tricky

What exactly is a calorie?Amount of energy needed to raise 1 g of water 1 degree Celsius

Ranges of Metabolic Rates

• Minimal rates– Support basic functions

to maintain life

• Maximum rates– During peak activities

The In-between:Affected by age, sex, size, body temp, env temp, foods, activity

levels, oxygen availability, hormones, and time of day

Endotherm

• Maintain body temperature to sustain life

• Metabolism generates heat to warm body

• More Calories to sustain life

Ectotherm

• Absorb heat from external environment

• Less Calories to sustain life

Basal Metabolic Rate (BMR)

• Endotherms• At rest• Empty stomach• No stress• 1600-1800 kcal per day for

adult males• 1300-1500 kcal per day for

adult females

Standard Metabolic Rate (SMR)

• Ectotherms• Changes along with

environmental temperature (as does body temperature)

• Determined at specific temperatures for an ectotherm at rest, with an empty stomach and no stress

The amount of energy it takes to maintain each gram of body weight is inversely related to body size!!

(Each gram of a mouse consumes about 10X more calories than a gram of an elephant)

Internal Regulation(Page 788)

• Regardless of external surroundings

• Body temp 37⁰C (98.6⁰F)• pH of blood and interstitial

fluid within a tenth of 7.4• Sugar in blood at 0.1%

• Homeostasis- dynamic equilibrium

• How does each system work with each other?

Animal Nutrition(Pages 792-796)

• Nutrition diet serves three purposes:

• ATP for cellular work

• Carbon skeletons for biosynthesis

• Essential nutrients

Regulation of Cellular Fuel

• If more calories are consumed than are needed to meet energy requirements…

• we store the excess calories as…• glycogen (polymer of glucose)• What hormone monitors glycogen?

How does it go?

• Digest food → glucose goes into blood → too much glucose (ate too much) pancreas releases insulin → glucose gets transported and liver and muscle store it as glycogen → blood glucose goes down until a certain point → pancreas secretes glucagon so glycogen is broken down and blood glucose goes up

Regulation of the Glycogen

• Where is glycogen stored?

• What are insulin and glucagon?

• What does the liver have to do with it?

• When does glycogen get broken down?

Click for video

SOOOOO what did we learn about diabetes and its negative effects????

Pancreas secretes most of our digestive enzymes too

Leptin and appetite

• What type of molecule?• Who produces it?• High leptin decreases appetite and increases

energy-consuming muscular activity• Decreases in leptin (due to decreased body

fat) signals an increase in appetite and weight gain

Body’s ability to fabricate

• Carbohydrates are made up of what elements?

• Amino acids add what element?• “An animal can fabricate a great variety of

organic molecules. A single type of amino acid can supply nitrogen for the synthesis of several other types of amino acids that may not be present in food.” (Bio textbook)

Malnourished versus Undernourished

Essential Nutrients

• Nutrients that the body canNOT make from any raw materials

• Must be consumed• Differ between species• Human example: Vitamin C• Four classes:– Amino acids (20 total, 8 are essential)– Fatty acids – Vitamins– Minerals

Essential Amino Acids

• 8 for adults; 9 for children (histidine-in formula)

• Sources: meat, eggs, cheese, other animal products

• Plant sources are deficient in one or more• Combination is key• Each essential must be consumed

each day-cannot be stored

Essential Fatty Acids

• Unsaturated…what does that mean again??

• Why needed…membrane integrity

Vitamins

• Small amounts are required but deficiencies can cause severe problems

• 13 essential• Water-soluble or Fat-soluble

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What do they do for us?(humans)

• Vitamin B12: Nucleic Acid metabolism; RBCs• Vitamin C: Collagen (connective tissue-bones);

antioxidant and detoxifier • Vitamin D: bones and calcium absorption• Vitamin E: antioxidant; lipids of membranes

Minerals

• Inorganic• Requirements vary with animal species

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What do they do for us?(humans)

• Calcium: Bones, nerves, and muscles• Phosphorus: Bone, ATP, DNA• Potassium: Osmotic balance, nerve function• Sodium: Osmotic balance, nerve function• Iron: Cellular respiration, hemoglobin (oxygen

transport)

Digestion

“After chewing and swallowing, it takes only 5 to 10 seconds for food to pass down the esophagus and into the stomach, where it spends 2 to 6 hours being partially digested. Final digestion and nutrient absorption occur in the small intestine over a period of 5 to 6 hours. In 12 to 24 hours, any undigested material passes through the large intestine, and feces are expelled through the anus.” (Figure 41.11 Page 801)

Pages 803-804 (Digestion of macromolecules)

• Small intestine is the location of most enzymatic hydrolysis of macromolecules

• Also the location of most nutrient absorption into the blood

• Duodenum: first portion of the small intestine• Pancreas, liver, and gallbladder all secrete

digestive juices to aid the small intestine (intestinal wall also secretes enzymes)

Carbohydrate Digestion

• Salivary Amylase:• Pancreatic amylases:• Disaccharidases: disaccharide digestion is

specific to the sugar (maltose=maltase; lactose=lactase)

• Where are disaccharidases located?• Last step?

Protein Digestion

• Pepsin:• Trypsin/chymotrypsin:• Carboxypeptide:• Aminopeptidase:• Dipeptidases/aminopeptidase:• Who secretes each? Where?• Enteropeptidase:• Figure 41.14

Nucleic Acid Digestion

• Nucleases:• Nucleotidases/nucleosidases:• Where?

Fat Digestion

• Does not being digesting AT ALL until…• Fats are insoluble in water (hydrophobic)• Bile salts (gallbladder)/emulsification:– Coalescing (to come together and form one

mass/whole)• Lipase:

Describe how a disease is the result of a malfunctioning system organ and cell and relate this to possible treatment interventions (e.g. diabetes cystic fibrosis lactose intolerance).

Cite evidence that the transfer and transformation of matter and energy links organisms to one another and to their physical setting.

Use mathematical formulas to justify the concept of an efficient diet.

Predict what would happen to an ecosystem if an energy source was removed.

Explain how the process of cellular respiration is similar to the burning of fossil fuels.

So what do you eat in a day??