Chapter 37 & 41 Flashcards
Autotrophs
Self-Feeders: require inorganic form of carbon
ex: CO2, HCO3-
Inorganic
Not from living organism
Organic
From living organism
Heterotrophs
Other Feeders: require organic carbon
ex: C6H12O6
Phototrophs
Light Feeder: obtains energy from light
Chemotrophs
Chemical Feeder: obtains energy from chemicals
Photoautotrophy (3)
- Convert light energy into chemical energy
- power synthesis of energetically unfavourable molecules (carbohydrates) - Includes plants, algae and cyanobacteria
- Photosynthetic organisms absorb light in the visible spectrum
- PAR
- 40% of incident radiation
PAR
Photosynthetically Available Radiation
Specialized structures that capture energy (3)
- Leaves (plants)
- Blades (microalgae)
- Chloroplasts (all, including microalgae)
How is energy converted in chloroplasts?
Light energy is converted to chemical energy
2 moles of NADPH and 3 moles of ATP are used for what?
To fix a mole of CO2
Efficiency of Energy Acquisition (3)
- Capture is inefficient
- Conversion is efficient
- 5% of solar energy is retained by the biosphere
Chemoheterotrophy (3)
- Energy and carbon directly or indirectly form autotrophs
- Includes prokaryotes, protists, fungi, animals and some plants
- Food is processed to obtain carbon, nutrients and energy
What are the 4 steps for how animals process ‘food’?
- Ingestion
- Digestion
- Absorption
- Elimination
*some heterotrophs skip a step or two
How do fungi eat? (2)
- Fungi are absorbers*
1. Decomposers secrete enzymes to break down dead material (e.g. deterius)
2. Other fungi pierce plants or animal bodies with hyphae, and extract nutrients
Ingestion (4 Feeders)
- Suspension/filter Feeder
- Substrate Feeder
- Fluid Feeder
- Bulk Feeder
Suspension/Filter Feeder
Traps small organisms or particles from water (many aquatic animals)
Substrate Feeder
Live on or in their food source
- Herbivores
- Carnivores
- Omnivores
- Detrivores
Fluid Feeder
Suck nutrient-rich fluid from host
Bulk Feeder
Ingest relatively large pieces of food (often with specialized teeth)
Ingestion - Dentition and Diet
Herbivores:
-broad, rigid molars and premolars for grinding
Carnivores
-large incisors and canines that serve as weapons, and premolars that shred meat
Omnivores:
-somewhere in the middle
Digestion + (2 Types)
Break down food into molecules small enough for absorption
- Mechanical
- Chemical
Mechanical Digestion
Chewing in some animals, crops and gizzards in birds
Chemical Digestion
Enzymatic hydrolysis
How does digestion typically begin?
Extracellularly
-gastrovascular cavity (simple animals): first stages of digestion breaks down large prey then moves onto smaller
Respiration (2)
- Photoautotrophs and chemoheterotrophs BOTH respire
2. Release energy from organic compounds and start synthesis of other macromolecules from precursors
Other Nutrient Requirements (5)
- Elements
- Essential Minerals (Humans)
- Amino Acids
- Others
- Essential Minerals (Plants)
Elements
- organisms require a range of chemical elements
- essential elements: can’t complete life cycle without
Essential Minerals (Humans)
Obtained through diet.
ex: sodium, calcium, iron etc.
Amino Acids
- animals require 20 amino acids
- essential amino acids: must be obtained from diet (rest can be synthesized)
Others
- Water and fat: soluble vitamins come straight from diet
- Fatty acids from diet (unsaturated)
Essential Minerals (Plants)
- Macronutrients (required in large amounts)
- Micronutrients (required in small amounts)
- Almost all acquired through soil via roots
Mineral Uptake - Plants
- an active process
- proton pumps!
Proton Pumps
Roots pump H out of cytosol, leaving it electrically negative and slightly alkaline
- cations enter passively
- anions co-transported with H
- after h2o, N is typically the next limiting element
