Campbell Biology Chapter 41

The process where food is taken in, taken apart, and taken up

animal nutrition

Animals fall into three categories

Herbivores, carnivores, and omnivores

Most plants and animals are also

opportunistic feeders

An animals diet must provide 3 things

chemical energy for cellular processes, organic building blocks for macromolecules, and essential nutrients

Materials that an animal cannot assemble from simpler organic molecules are called

essential nutrients

There are four classes of essential nutrients

essential amino acids, essential fatty acids, vitamins, and minerals.

Animals require about _____ amino acids and can synthesize about half from molecules in their diet

20

The essential amino acids can be obtained from

food

Animals can synthesize most of the ______ they need

fatty acids

Essential fatty acids must be obtained from

diet

Vitamins

organic molecules required in the diet in very small amounts

how many vitamins are essential for humans

13

two categories of vitamins

fat-soluble and water-soluble

Vitamin requirements of humans

B2, b3, c, a ,d underlined on the slide.

Minerals

simple inorganic nutrients, usually required in small amounts

Mineral requirements of humans

Ca, k, mg, fe, i

malnutrition

failure to obtain adequate nutrition

Undernutrition

diet does not provide enough chemical energy

An undernourished individual will

use up stored fat and carbs, break down its own protein, lose muscle mass, suffer protein deficiency of the brain, die or suffer irreversible damage

Epidemiology

the study of human health and disease in populations

Ingestion

the act of eating or feeding

4 steps of food processing

Ingestion, digestion, absorption, and excretion

Suspension feeders

sift small food particles from the water

Substrate feeders

animals that live in or on their food source

Fluid feeders

suck nutrient rich fluid from a living host

Bulk feeders

eat relatively large pieces of food

Digestion

the process of breaking food down into molecules small enough to absorb

Mechanical digestion

ie: chewing. increases the surface area of food

chemical digestions

splits food into small molecules that can pass through membranes, these are used to build larger molecules

absorption

uptake of nutrients by body cells

elimination

passage of undigested material out of the digestive system

In intracellular digestion food particles are engulfed by

phagocytosis

Complex animals have a digestive tube with two openings, a mouth and an anus

complete digestive tract or and alimentary canal

The mammalian digestive system consists of an _______ and ______ glands that secrete digestive juices through ducts

alimentary canal and accessory

Peristalsis

Rhythmic contractions of muscles in the wall of the canal

Sphincters

valves that regulate the movement of material between compartments

The human digestive system

human digestive system

The first stage of digestion is mechanical and takes place in the

oral cavity

Salivary glands

deliver saliva to lubricate food

teeth chew food into smaller particles that are exposed to salivary

amylase

amylase

initiates breakdown of glucose polymers

Saliva also contains

mucus

mucus

a viscous mixture of water, salts, cells, and glycoproteins

The tongue shapes food into a _____ and provides help with swallowing

bolus

The throat, or _____ is the junction that opens to both the esophagus and the trachea

pharynx

The ______ connects to the stomach

esophagus

The ______ (windpipe) leads to the lungs

trachea

Swallowing causes the _____ to block entry to the trachea

epiglottis

The stomach

stores food and begins digestion of proteins

the stomach secretes ______ which converts a meal into ______

gastric juice and chyme

Gastric juice is made up of ______ and ______

Hydrochloric acid and pepsin

pepsin is a ______ or protein digesting enzyme that cleaves proteins into smaller peptides

protease

What cells secrete hydrogen and chloride ions separately into the lumen of the stomach

Parietal cells

_____ cells secret inactive pepsinogen

Chief

Pepsinogen

is activated to pepsin when mixed with HCl in the stomach

The longest compartment of the alimentary canal is the

small intestine

The first portion of the small intestine is the

duodenum

The duodenum mixes

chyme from the stomach with digestive juices from the pancreas, liver, gallbladder, and small intestine

Chemical Digestion

Pancreas produces

proteases called trypsin and chymotrypsin that are activated in the lumen

Bile

aids digestion and absorption of fats

Bile is made in the

liver

bile is stored in the

gallbladder

Most digestion occurs in the _______

duodenum

The small intestine has a huge surface area due to

villi and microvilli that are exposed to the intestinal lumen

Hepatic portal vein

carries nutrient rich blood from the capillaries of the villi to the liver, then to the heart

Fats that are coated with phospholipids, cholesterol, and proteins that form water soluble

chylomicrons

Chylomicrons and transported into a _____

lacteal

lacteal

lymphatic vessel in each villus

Colon of the large intestine is connected to the

small intestine

The cecum aids in fermentation of _____ and connects where the small and large intestines meet

plant material

The human cecum has an extension called the

appendix

Feces

undigested material and bacteria, become more solid

Feces are stored in the

rectum

Ruminant digestion

The endocrine system aslo

regulates digestion through the releases and transport of hormones

hormonal control of digestion

In humans, energy is stored first in the ____ and ____ cells in the polymer glycogen

liver and muscle

The hormones _____ and ______ regulate the breakdown of glycogen into glucose

insulin and glucagon

The _____ is the site for glucose homeostasis

liver

insulin acts on nearly all body cells to stimulate ____ uptake from blood

glucose

Glucagon and insulin are both produced in the islets of the ______

pancreas

alpha cells make

glucagon

beta cells make

insulin

Diabetes mellitus

caused by a deficiency of insulin or a decreased response to insulin in target tissues

Type 1 diabetes

autoimmune disorder in which the immune system destroys the beta cells of the pancreas

Type 2 diabetes

characterized by a failure of target cells to respond normally to insulin

Ghrelin

triggers hunger

Insulin and PYY

suppress appetite

Leptite

suppresses appetite and regulates body fat levels