Chapter 41: Animal Nutrition Flashcards
Energy is stored in human tissues and cells as…
ATP
ATP is released as…
heat from the surface of our bodies
The entire biosphere relies on _____ to convert the sun’s energy to organic fuel from the sun’s energy.
producers
4 types of consumers
herbivore, carnivore, omnivore, detritivore
Consumers
heterotrophic; cannot create food molecules, they must obtain them from other organisms; cannot perform photosynthesis; must get energy from sun through plants
Producers
autotrophic; assemble usable food molecules through photosynthesis or chemosynthesis
An adequate diet must satisfy three nutritional needs:
- chemical energy for cellular processes and maintaining homeostasis
- organic building blocks needed to synthesize the carbon molecules that form the body and for biosynthesis
- provide essential nutrients (molecules that the body is incapable of synthesizing and that must be ingested)
cellular respiration
Energy (in the form of ATP) is extracted from food by oxidizing carbohydrates (CHOs), proteins, and fats
biosynthesis
the process of building components for the body like proteins
Carbohydrates are broken down to
Smaller sugar molecules
Proteins are broken down into
amino acids
Fats are broken down into
fatty acids
The four classes of essential nutrients:
- Essential amino acids
- Essential fatty acids
- Vitamins (function as coenzymes)
- Minerals (function as cofactors)
How do strict herbivores survive on a vegetarian diet?
They eat a variety of plant tissues and plant species, ingest large quantities of plant materials, and have specialized digestive tracts with symbiotic bacteria and protozoa.
“complete” proteins
provide all the essential amino acids (i.e. meat, eggs, cheese)
plants have a high _____ ratio
C:N
Lipids and fatty acids are necessary for
building cell membranes and synthesizing some hormones
Animals can synthesize most of the fatty acids they need from….
Seeds, grains, vegetables
The essential fatty acids must be obtained from the diet and include…
certain unsaturated fatty acids (1 or more double bond)
Vitamins and minerals are…
Micronutrients
Vitamins and minerals are not _______; but used _____
broken down; in tact
Vitamins
organic molecules required in the diet in very small amounts
Minerals
simple inorganic nutrients, usually required in small amounts
Ingesting large amounts of some minerals can…
upset homeostatic balance
needed in large amounts to form the matrix of bone
Calcium and phosphorus
needed for function of nerves and muscles
Calcium
needed for building nucleic acids
Phosphorus
digestive system
breaks down food and prepares nutrients for circulation through the blood so that nutrients reach every cell in our body
_____ have the shortest and simplest digestive tracts and large, expandable stomachs
Carnivores
_____ and _____ have longer alimentary canals, reflecting the longer time needed to digest vegetation
Herbivores; omnivores
Ruminant Adaptations
- Longer alimentary canals
2. Pouches that house bacteria and protists that can break down cellulose – enlarged cecum and multi-chambered stomach
Ruminant
large herbivorous animals that have a four chambered stomach and “chew the cud” to increase efficiency of digestion of cellulose (deer, cattle, sheep)
What are special digestive adaptations of frugivores?
Their digestive system is adapted such that they can consume a large number of fruits without affecting the seeds in a negative way
Fruit bat adaptations
Short digestive time
Large liver
No caecum or appendix
Short large intestine
Substrate Feeders
live on or in their food source (i.e. caterpillars)
Fluid feeders
suck nutrient-rich fluid from a living host (e.g., mosquitoes)
Filter feeder example
Baleen whales
Suspension feeders
sift small food particles from the water (e.g., fan worm, hydra)
Bulk feeders
Eat relatively large pieces of food (snakes)
4 stages of digestion
- Ingestion
- Digestion
- Absorption
- Elimination
coprophagy
consuming own feces for additional nutrients
Ingestion
foods and liquids are taken into the digestive compartment
Digestion
food is broken down by both mechanical and chemical processes
Absorption
the epithelial cells lining the GI tract absorb the digested food molecules and pass them to the blood or lymph.
Elimination
any substance not digested or absorbed, for whatever reason, is passed along to the end of GI tract, the anus, and leaves the body
Mechanical digestion
Chewing; increases surface area of food
Chemical digestion
splits food into small molecules that can pass through membranes; these are used to build larger molecules
enzymatic hydrolysis
splits bonds in molecules with the addition of water
How do sponges feed?
In order obtain food, sponges pass water through their bodies in a process known as filter-feeding. Water is drawn into the sponge through tiny holes called incurrent pores (intracellular)
Gastrovascular cavity
digestive pouch with one opening where food is ingested and wastes are eliminated; digestion is extracellular
Intracellular digestion
each cell engulfs food particles in food vacuoles; digestion occurs when a food vacuole fuses with a lysosome containing digestive enzymes
Alimentary canal
digestive tube with two openings (mouth and anus); digestion is extracellular; most common digestive compartment in animals
In the oral cavity, ______ deliver saliva to lubricate food.
Salivary glands
salivary amylase
initiates breakdown of glucose
The tongue shapes food into a
bolus
pharynx
the junction that opens to both the esophagus and the trachea (throat)
esophagus
connects to the stomach and conducts food from the pharynx down to the stomach by peristalsis
peristaltic wave
rhythmic muscular contractions
stomach
a J-shaped organ that lies beneath the esophagus; churns and mixes the bolus with the stomach acids and begins protein digestion; converts food into chyme
chyme
partially digested food
Pyloric sphincter
separates stomach from small intestine; opens to allow chyme enter the small intestine only when it is chemically ready
rugae
Folds in the stomach walls that permit expansion somewhat like a deflated punching ball
pH of stomach
2
thick, viscous, alkaline mucus
protects stomach from its own acids
Gastric juices secreted by stomach
- pepsin (breaks down proteins)
- gastric lipase (breaks down fats)
- HCl (kills microbes and denatures proteins)
- factors that assist in absorption of vitamin B12
Vitamin B12
necessary for creation of blood cells
small intestine
the only portion of the GI tract where nutrients are taken into the cells and where nutrients are absorbed
Once in the small intestine, the chyme stimulates the release of hormones which affect….
Liver, pancreas, and gallbladder
The villi of the small intestine increase
Surface area allowing for better absorption
mitochondria
convert glucose into ATP
capillaries in the villi
deliver nutrients to the body
pancreas
makes insulin and glucagon, hormones that are responsible for regulating glucose uptake by the cells
liver
largest organ; monitors blood from small intestine; cleanses blood before it goes to the heart; monitors the glucose level in the blood
Cholesterol, plasma proteins, and blood lipids are manufactured in
liver cells
When blood glucose level exceeds 0.1%….
liver cells remove and store the excess as glycogen
gallbladder
a small organ that aids in digestion and stores bile produced by the liver
Bile
formed by the liver as a by-product of the breakdown of hemoglobin and cholesterol; breaks larger fat globules into smaller ones.
large intestine function
reabsorb the water that was added to the chyme to begin digestion
large intestine parts
colon, caecum, appendix, rectum, and anus
Compacted chyme
feces
When the feces move into the rectum and press against the external anal sphincter, this triggers
Defecation
______ propels feces into the rectum
Peristalsis
What expels feces?
Skeletal muscles
Humans and great apes (bonobos, chimpanzees, gorillas, and orangutans) share a common gut anatomy, but what is different about them?
great ape: large intestine is majority of the gut
humans: small intestine is the majority of the gut
