Animal: Lecture 4 Flashcards
Why do animals eat?
- Maintain metabolic rate for cellular activites
- Get minerals and vitamins that they otherwise wouldn’t get (can’t make by themselves)
- Carbohydrates (building blocks for new things)
- All physiological functions require energy (chemical ~> ATP) and/or matter (carbon skeletons)
- All animals are heterotrophic and have to obtain energy from other things.
What is bioenergetics?
Bioenergetics is the overall flow and transformation of energy within an organism.
Where is chemical energy stored?
It is stored in the bonds of fat molecules, protein molecules, carbohydrate molecules.
- They must be broken to be absorbed
Ways energy comes in?
Energy comes in as food, is converted to chemical energy (ATP) which is used for metabolism.
What ways is energy lost?
- Chemical waste (CO2 and H2O)
- Heat from ATP conversion
- Heat from metabolism
What processes lose energy?
- Heat lost from digestion and absorption
- Energy lost in faces from digestion and absorption
- Energy lost in nitrogenous waste (urea) from nutrient molecules in body cells.
- Heat lost from cellular respiration
- Heat lost from cellular work
- Heat lost from biosynthesis
Process of moving energy?
- Organic molecules in food
- Digestion and absorption
- Nutrient molecules in body cells
- Cellular respiration
- ATP
- Cellular work
- Biosynthesis
What is biosynthesis?
Carbon skeletons and cellular work allow biosynthesis to occur. Biosynthesis is used for body growth, repair, fat storage, gamete production.
How much energy does an animal need
- Enough to maintain their basic metabolic functions (maintain cellular activity, blood flow, respiration, temperature of body)
- The more active an animal is, the more energy is needed (moving, eating, growing, mating, etc.)
- Depends on the size of the organism and how effective they are at using their energy.
What is metabolic rate?
Amount of energy used per unit time.
What is Basal Metabolic Rate (BMR)?
The metabolic rate of a non-growing endothermic that is at rest, has an empty digestive tract, and is not experiencing stress.
- The minimum amount of energy to maintain basic functions
What could you use to measure an animal’s energy use?
- Heat production
- Oxygen consumption
- Carbon dioxide production
- Food consumption
- Waste production
Why couldn’t we measure the BMR of a juvenile sea lion?
It is still growing (juvenile).
What are things we could measure in different animals?
- Measuring energy cost flight in a bird
- Measuring resting metabolic rate of a juvenile sea lion.
- Measuring energy cost of swimming in a shark.
Which animal eats more?
Mouse or Elephant?
Depends on what we measure:
- Absolute/total amount
- Amount per unit body weight
Metabolic rate depends on size?
BMR = Mass ^ 0.75
Elephants vs. mice absolute BMR?
Elephants have a higher absolute BMR and need more food overall.
Metabolic rate depends on unit/body mass (ex. per kg)?
Elephants have a BMR for each kg, and therefore use energy more efficiently.
Therefore, which animal eats more?
- The mouse eats more per unit body mass (~12-13% of body weight)
- The elephant eats more in absolute terms (~4-6% of body weight)
An animal’s diet must supply what?
Energy, organic molecules, and essential nutrients.
Chemical energy is used..?
Chemical energy in food is used in cellular respiration to produce ATP or is stored.
Organic molecules are needed for?
Organic molecules are needed for biosynthesis.
- Nucleic acids, carbohydrates, proteins and lipids.
What are essential nutrients?
Essential amino acids, essential fatty acids, vitamins, and minerals.
What functions are carried out by digestive systems?
Ingestion (food handling)
Digestion (break down of food into absorbable components)
Absorption (nutrient molecules enter body cells)
Elimination (removal of undigested material - faces, urea)