Chapter 30 Nutrition, Feeding and Digestion Flashcards
Animals are heterotrophs. What does this mean
Gain energy and building blocks from ingesting other organsisms (instead of from light energy like plants)
How is energy content of food measured?
By amount of heat produced when completely burned in the presence of O2, producing CO2 and H2O
What is a joule?
0.239 calories
How much energy is produced by lipids, carbohydrates and proteins?
Lipids - 9.4 kcal/g
Carbohydrates - 4.1 kcal/g
Proteins - 4/5 kcal/g
What is metabolic rate
Amoun of energy an animal converts to heat per day
How is most energy stores?
As lipids (most energy stored per gram) Animals also store as glycogen (approx 1 kcal/g) which breaks down into glucse and is needed for brain and anaerobic glycolysis
What Are essental nutrients
Ones that are required but cannot be synthesized by the animal
How many standard amino acids are there?
20 that animals need to build proteins. Some can be syntheized
What are the essentail fatty acids that humans require
Require a-linoleic acid and linoleic acid which they can get from omega-3 and omega-6 fatty acids
What essential nutrients are there
Calcium 0 neede din large amounts
Mosta re needed in small amounts - iron for haemoglobin and myoglobin
What is the result of nutrient deficiency
malnutrition - chronic malnutrition leads to deficiency disease
- Scurvy - vitamin C deficiency
- Beriberi - Vitamin B1
what are the 3 main ways animals get food
Target large easily visible individual food items
Suspension feeding - tiny particles in large numbers filtered from water
Symbiosis
Define symbiosis
close long-term associated beween 2 tyes of organisms
e.g. aimals and microbes that synthesize important nutrients
What is the symbiotic relationship between Reefbuilding coals and algael cells
Algal cells produce glucose by photosynthesis and give pigments colour
Provide food for animals
What is unique about ruminant mamals (cows, sheep, deer etc.)
Stomach with 4 champers
break down food by fermentation via community of bacteria, protozoa, yeasts and fungi
- Allows digestion of cellulose that vertebrates cannot breakdown and production of some B vitamins and essential amino acids
- Nitrogen recycled - used by microbes to build proteins that animal digests
Why are heterotropbic microbes important
allow breakdown of things vertebrate otherwise could not
humans have large gut microbiome
What is the main structure of the digestive tract in aimals
Tubular - food enters mouth, indigestible materials exit at anus
Lined with epithelium
What are the functions of the digestive tract
Digestion - breakdown of food molecules
Absorption - transport of small molecules from gut lumen into blood
How does digestive ability determin nutritional value of food
Digestive enzymes are specific to what type of bonds they can breaks. Ability to digest determined by enzymes produced
If they cannot digest food, there is no nutritional value
What is Trehalose
enzyme in animals that eat insects - breaks down sugar abundant in insects
Why is lactase more prominent in northern europeans
It breaks down lactose - due to high dairy diet
Can animals modify digestive enzymes?
Yes - e.g rats go from low to high protein diet start producing protein digestion enzyme in 24 hours
What are the layres of the digestive tract
Mucosa - Epithelium (contains digestive-absorptive cells) - Underlying connective tissue Submucosa - blood and lymph vessels Smooth Muscle
What are the 2 layers of muscle in the gut
Circular (innermost)
Longitudinal (outerost)
