Lecture 17 & 18 - Energy Acquisition Flashcards
all life is built out of _______
complex carbon molecules
Autotrophs vs Heterotrophs
Autotrophs
- > require only an inorganic form of C (i.e. CO2, HCO3)
Heterotrophs
- > require organic C (i.e. C6H12O6)
organic = from living organism
organic macromolecules are ____________
energetically unfavorable
- > synthesis requires input of energy
i. e. phototrophs and chemotrophs
from where do phototrophs and chemotrophs obtain energy from
- > Phototrophs obtain energy from light
- > chemotrophs obtain energy from chemicals
Photoautotrophy
- > the process by which organisms convert radiant energy from the visible spectrum into biologically useful energy (organic photosynthesis) and synthesize metabolic compounds using only carbon dioxide or carbonates as a source of carbon
- > includes plants, algae and cyanobacteria
energy is captured in which specialized structures
- > leaves (plants)
- > blades (microalgae)
- > chloroplasts (all, including microalgae)
How is light energy converted into chemical energy within the chloroplasts
is energy acquisition in photoautotrophy efficient
chemoheterotroph
- > the term for an organism which derives its energy from chemicals, and needs to consume other organisms in order to live
- > energy and carbon directly or indirectly from photoautotrophs
- > includes prokaryotes, protists, fungi, animals and some plants
what are the four stages of animal food processing
explain how some heterotrophs skip a step or two of food processing
fungi are absorbers
- > decomposers secrete enzymes to break down dead material
- > other fungi pierce plant or animal bodies, and extract nutrients
Different types of ingestion
- Suspension/ filter feeders
- > trap small organisms or particles from water (many aquatic animals; whales) - Substrate feeder
- > live on or in their food source (many insects) - Fluid feeders
- > suck nutrient-rich fluid from host (i.e. hummingbird or mosquito) - Bulk feeders
- > ingest relatively large pieces of food; something bigger than its own diameter
- > often have specialized numbers and types of teeth
Explain how the dentition relates to the diet of herbivores, carnivores and omnivores
Herbivores
- > broad, ridged molars and pre-molars from gringing plant material
Carnivores
- > large incisors and canines that serve as weapons and (pre)molars that shred meat
Omnivores
- > somewhere in the middle
Digestion
the breakdown of food into smaller molecules enough for absorption
- > breaks down into components through…
Mechanical
- > chewing in some animals, crops and gizzards in birds (this increases surface area for digestion)
Chemical
- > enzymatic hydrolysis
where does digestion usually begin in chemoheterotrophs
usually begins extracellularly
gastrovascular cavity (simple animals):
- > first stages of digestion break down large prey
- > food particles then ingested by phagocytosis for intracellular digestion
Alimentary canals (more common): two openings and uni-directional food movement
- > ingest food while processing previous meal
- > enables evolution of larger animals
essential minerals (humans)
Essential minerals (plants)
macronutrients: required in large amount
micronutrients: required in small amount
- > they obtain essential minerals from soil
how does the active uptake of minerals work on a cellular level
the proton pump
- > roots pump H+ out of the cytosol, leaving it electrically negative and slightly alkaline
- > cations enter passively (down electro chemical gradient, against conc. grad)
- > anions contransported with H+ (against elec. and conc. gradients)
