Midterm 1 Flashcards
(122 cards)
Descent with modification
o Ancestor gave rise to diversity. We all come from one common ancestor
Food webs
o Energy and nutrients are transferred between organisms in an ecosystem as they compete for light or are consumed by other organisms
o Structure of food web is determined by the amount of energy at any trophic level
Symbiotic Interactions
o Long term interactions between organisms
♣ Positive = mutualism
• Ex. Cooperation between ant-plants and plants
♣ Negative = parasitism
♣ Neutral = Commensalism
Food Chain/Trophic Levels
- Primary producer -> primary consumer -> secondary consumer -> etc.
- Photosynthetic organisms- at base. Take energy from the sun and use that energy to make carbohydrates
- Energy is lost from the system by heat as they pass from one trophic level to the other
How is energy lost between trophic levels?
Cell respiration
feces/waste management
growth
reason why there are less orgs at each trophic level
Feed conversion ratio
Amount of feed : weight gain
Gross Primary Productivity (GPP)
Total amount of CO2 that is fixed by plants through photosynthesis = energy captured
Net Primary Productivity (NPP)
o Gross primary productivity minus the energy used by plants for their own growth and respiration = energy available to other organisms
♣ NPP = GPP – R
Carbon Cycle
o Photosynthesis Organic Carbon Animal Respiration and Plant Respiration Photosynthesis
Human appropriation of net primary productivity
basically when we steal from the primary productivity directly
Food:plants, animal products
Fiber:construction, paper, clothing
Fuel:wood, oil, gas
how many nutrients required for life
Macronutrients: acquired from air and water
CarbonHydrogenOxygenNitrogen
Micronutrients: acquired from the soil
21 other elements
Micronutrient deficiency diseases
o Iodine (goiter) o Iron (anemia) o Calcium (osteoporosis)
Macromolecules
Carbohydrates
Lipids (fats and oils)
Proteins
Nucleic acids (DNA and RNA)
Small molecules
Vitamins
Minerals
Phytochemicals
Uses of chemicals in food
- Structural: components of cells and tissues (proteins, cell walls, bones, cuticle, etc.)
- Energy: breakdown of complex molecules releases energy, which is used to power all of a cell’s activities.
- Metabolic: facilitate enzymatic reactions, osmolytes, membrane potential etc.
Where is energy of food stored?
The energy in food is stored as covalent bonds, and this energy is released, and can be used for other activities, when these bonds are broken.
What determines melting temperature of fat?
Number of double bonds
Humans and amino acids
Humans can synthesize 12 of the 20 amino acids. The remainin 8 (“essential”) must be obtained from food.
Vitamin A
retinol, photoreceptor pigments in retina of the eye; growth factor; immune system; antioxidant
Vitamin B3
precursor of NAD and NADP which are involved in many metabolic processes
Vitamin C
Co-factor in the enzymatic reactions that produce collagen; antioxidant
Alkaloids
“ine” ending, contain nitrogen and affect our nervous system
Terpenoids
diverse, complicated structures
Phenolics
basis for the flavor and color of many plants