lecture 4 animal Flashcards
why do animals eat
all physiological functions require energy (chemical, atp) and/or matter – carbon skeletons to build various structures
– all animals are heterotrophic, the consome other organisms for food
bioenergetics
overall flow and transformation of energy within organism
basic overview of bioenergetics
– organic molecules in food enter through consumptopon – digestion absorption – energy lost in form of heat and in feces – nutrient molecules in body cells – energy lost in nitrogenous waste (urine) – cellular respiration – heat loss – atp – ceullular work heat lost – and viosysntheis heat is lost
biosynthesis
making new things in body with building blocks (carbon skeletons) – growth, repairing, storing, gamete productioin..
how much energy does an animals need?
enough to maintain basic metabolic function – maintain cellular activity, blood flow, respiration, temperature – very minimum amount
the more active animal is, more energy is needed
metabolic rate
amount of energy used per unit time – what dictates amount of energy youre going to need
basal metabolic rate (BMR)
metabolic rate of NON-GROWING endotherm that is AT REST, has an EMPTY DIGESTIVE TRACT, and is NOT EXPERIENCING STRESS – minimum amount of energy to maintain basic functions
what could you measure to determine animals energy use
heat production, oxygen consumption, carbon dioxide production (respiration) , food consumption/waste production
what does metabolic rate depend on
activity, size and unit/body mass
metabolic rate depends on activity – examples
measuring resting metabolic rate of juvenile sea lion – not basal because it is still growing
physiologists also interested in how much energy is being used – mseasuring energy of flight in a bird – measuring energy of swimming in a shark
metabolic rate depends on size examples
elephants have a higher ABSOLUTE BMR – which means they need more food overall than a mouse
metabolic rates depends on unit/body mass
elephants have a LOWER BMR than mouse for each Kg because mouse is consuming more O2 per kG than elephant – mouse eats more per unit body mass but elephant eats more in absolute terms``
what three things must an animal’s diet supply
energy, organic molecules, and essential nutrients
chemical energy in food..
used in cellular respiration to produce ATP or is stored
organic molecules are..
needed for biosynthesis (building blocks of our tissues..) ex: nucleic acids, carbohydrates, proteins, lipids
essential nutrients
things our body cannot produce on its own – amino acids, essential fatty acids, vitamins, minerals (vitamin C or calcium)
what functions are carried out by digestive systems
- ingestion (bringing food to mouth– food handling)
- digestion (break down of food into absorbable components
- absorption (nutrient molecules enter body cells)
- elimination (removeal of undigested material)
ingenstion
bring food to mouth
digestion
in mouth starts to both chemically and mechanically digest food (chemically = amylasy, mechanically = chewing)
absorption
once broken down into small enough pieces, have to absorb food in body cells (intestinal area)
elimination
get rid of undigested molecules
structures associated with ingestion are the most diverse part of the digestive system, why
differences in diet, herbivores vs carnivores – carnivores are usually chewing softer – herbivores – plants are harder – diff sizes, shapes of teeth
– huge variety of sources of food therefore animals have EVOLVED STRUCTURES that a;llow trhem to eat these various foods.
mammalian teeth reflect diet
herbivore: intense premolars and molars to grind down plant bits (cows)
carnivores: enlarged icisors and canines for gripping and shredding the animal theyre preying (lions, wolves)
omnivores: a little bit of everything – specialized on broader sources of foods (humans)
four main feeding mechanisms
– suspension feeders and filter feeders
– substrate feeders
– fluid feeders
– bulk feedersq
