Energy in Living Systems 115 Exam 2

fitness

an individual’s ability to produce viable, fertile offspring

commencialism

occurs when one species benefits but the other in unaffected (ie. epiphytic orchid benefits from growing on a tree but tree is unaffected)

competition

occurs when individuals use the same resources and ends up hurting both in end

consumption

occurs when one organisms eats or absorbs nutrients from another

mutualism

occurs when two species interact in a way that confers fitness benefits for both

infraspecific competition

competition within species

interspecific competition

competition between species

niche

range of resources used by a species

competitive exclusion principle

principle that two species cannot coexist in the same ecological niche in same area because one species will out compete the other

fundamental nuche

the total theoretical range of resources that a species can use

realized niche

the portion of a fundamental niche that a species actually occupies (usually due to competition)

fitness trade off

an inescapable compromise between two traits that cannot be optimized simultaneously

niche differentiation

resource partioning- organism faced with competition (and are loosing) start to exploit different resources over time

character displacement

evolutionary change that occurs in species traits, enabling a species to exploit different resources (ie Galapagos finches)

coevolutionary arms race

a series of adaption and counter of better defense and better attack

constitutive defenses

traits that help individuals avoid being eaten (ie. camouflage, quick escape, toxins, schooling, armor, and mimicry)

batesian mimicry

a harmless species resembles a dangerous one (ie. toxic and nontoxic frogs)

mullerian mimicry

two or more dangerous species resemble each other (ie wasps, bees, and yellow jackets)

inducible defenses

physical, chemical, or behavioral defensive traits that are induced in prey in response to being eaten (ie, mussels increase shell thickness in presence of crabs)

Levels of Ecological Organizations

1. Organisms: individual animal

2. Populations: a group of same species

3. Community: various groups of different species

4. Ecosystem: community and non-living environment

Nitrogen fixing bacteria

rhizobia and mycorrhizae

Mutualism between nitrogen fixing bacteria and plant roots

Plants provided leghemoglobin to rhizobia or mycorrhizae(fungi), which binds to oxygen and takes it away from the bacteria so nitrogenase in the bacteria/fungi can fix nitrogen needed for plant to grow and survive. This is important because nitrogenase is poisoned by oxygen and won’t be able to fix nitrogen if it comes in too much contact with it. Also, nitogrenase requires a lot of energy, and the plant roots provide that energy to the bacteria carrying that enzyme. TRADE OFF- plant provides energy and takes away oxygen, nitrogen fixing bacteria provides nitrogen

Heterocyst

A plant cell that contains nitrgoenase and NO photosynthetic pigmentation. Outlines compartmentalization and specialization because nitrogen fixation is able to occur in heterocyst without oxygen from photosynthesis posing the enzyme.

generalists

organisms that feed on a broad range of food

specialists

organisms that feed on one or a very small range of food

when generalists and specialists are in the same niche what happens?

specialists outcompete generalists because specialists are inertially “better” or more adapted to exploting their resource than generalist who exploit multiple. SO, generalists are forced to use a realized niche

exponential growth

no immigration/emigration happening, occurs with new species introduced to new environment. Expected population = r (growth rate) * N (current population

logistic growth

density- dependent, decrease in growth as population size approaches carrying capacity. expected population = r (growth rate) * N (current population) * {[K (carrying capacity) - N (current population]/ K (crying capacity)}

density dependent factors

1. habitt

2. competition for resources

3. predation pressure

4. disease

5. social stress

species richness

number of species in a community

species eveness

how evenly represented are these species in a community

why do communities differ in species richness?

1. climate: water availability/temperature/seasonality

2. resource abundance/primary productivity

3. area: large area= more species

4. environmental heterogeneity: differences within environment

5. shelter avalibilty

6. keystonespceis/interactions

7. history: geological history IE GLACIERS= less species

8. island communities: less diverse

keystone species

have a disproportionally large affect on community structure, relative to their abundance

types of keystone species

1. keystone predator (ie grey wolf in Yellowstone)

2. keystone prey/producers (ie krill in ocean bc so many depend on them)

3. keystone ecosystem engineers (ie beavers making dams, elephants knocking down trees in Savana)

GPP

Gross Primary Productivity: total amount of energy captures

NPP

Net Primary Productivity: how much of GPP is captured and incorporated in plant use . NPP=GPP- R (chemical energy lost via cellular respiration)

food chain

one possible pathway of energy flow (ie grazing food chain [producer-herbivor-predator] or de composer food chain [detritus-decomposer-predator])

food web

detailed description of all possible food chains in ecosystem

Why not all energy reaches different trophic levels?

1. consumption efficiency: portion of biomass actually eaten (ie only leafs of plant is eaten by deer)

2. assimilation efficiency: “digestion” portion of consumed energy actually absorbed/digested (ie bones and hair not digested

3. production effdecenty: “conversion” portion of absorbed energy that is converted to new biomass

Nutrient cycling

(also humans add to atmospheric pool of carbon dioxide by burning fossil fuels)

Life History Trade-Offs

phenological shifts

shifts in timing (ie winter coat

range shifts

moving across the landscape to track ideal climate conditions

How might biotic interactions influence shift responses?

Mating season changes, occupancy of shelter by other organisms, competition for resources if organisms move to different landscape

Permeability of substances

(also regular non polar molecules, like steroids, cross more easily than small non polar)

Fluidity

the ability of phospholipid in bilayer to move around and interact

What affects fluidity?

1. Temperature:colder the temperature, less fluidity

2. Saturation: more unsaturated, less fluidity

3. Cholesterol: more cholesterol, less fluid/more permeable

Intergral proteins

NONPOLAR so can bind and interact with non polar region of phospholipid bilayer. If were polar, it wouldn’t interact with non polar region and would change shape, and therefore function.

covalent bonds

share electrons and must have similar electron affinities

non polar covalent bonds

equal electron sharing, no charge

polar covalent bonds

unequal electron sharing due to one molecule have slightly higher electronegativity, partial positive and partial negative charge

ionic bonds

electronegativity difference exceeds 1.7 between atoms/molecules. forms when 1 atom gives up electron (s) and other takes it

Properties of water

1. polar

2. high specific het

3. high heat potential

4. expands when gets colder/ice is less dense than liquid state

5. capillary action: surface tension, adhesion, cohesion (all bc of hydrogen bonds)

6. readily forms hydrogen bonds

7. solvent fro polar and ionic substances

types of diffusion

active and secondary transport

Ion channels

selective protein pores in a membrane only allow certain ions in

Gated Channel

opens and closes. TWO types:

1. ligand gate: molecule will bind to channel to open/close its gate

2. voltage gated channel: charge environment determines whether gate will open/close

carrier protein

blind, flip release

osmosis

transfer of water across membrane

What makes an amino acid chain polar/nonpolar?

If it has a component with OXYGEN or NITROGEN bound to a hydrogen, giving it a partial positive and negative charge

Structure of phospholipid

non polar tails interact with each other and polar head face away from each other to make bilayer

Cholestral

cholesterol on membrane DECREASES PERMEABILITY (ability for stuff to pass through membrane)

protein synthesizing process

Ribosome reads mRNA and synthesizes protein→ gets developed more in rER → gets modified and sorted in Golgi apparatus → transport vesicles carry to designated destination based on ER localization signal

Pulse chase Experiment

1. Pulse: expose cells to high concentration of amino acids for short time. proteins made will be labeled with that amino acid

2. Chase: amino acid label is washed away and proteins made after won’t be labeled

Tracks movement and time of labeled proteins

ER localization signal

protein sequence at beginning of protein that determines destination of protein and whether it is synthesized in rER or a free standing ribosome.

Golgi Sorting Process

1. protein carry tags

2. proteins are sorted in Golgi based on tags

3. transport vesicles bud off the Golgi into destinations

4. transport vesicles attach and fuse at different destinations

Motor proteins

1. kinesin: “walks” on microtubule towards plus end and carries transport vesicle

2. dynein: changes shapes and moves adjacently towards minus of microtubule

both use ATP and is energetically costly

3 cytoskeleton components

1. Actin filaments: two coiled strands that maintain CELL SHAPE and resist tension, moves cell via muscle contraction and CELL DIVIDING

2. Intermediate filaments: fibers the twist around into thicker cables, RESISTENT TO MECHANICAL STRESS

3. Microtubules: hollow tubes that maintains cell shape, provides tracks fro active transport, INTERCELLULAR MOVEMENT

glycosylation

addition of sugars to proteins: amino acid is modified by adding sugar and IMPACTS protein folding, stability, cell to cell recognition, and protein function

process that occurs in Golgi

Trade offs of cytoskeleton

-energy consuming

-reduces flexibility and movement bc of extra stability

endocytosis

plasma membrane budding into vesicles

exocytosis

vesicle leaving cell -OR- vesicle merge to make membrane bigger

3 types of endocytosis

1. receptor-mediated: cell selectively absorbs specific target molecules only after they lock into matching receptor proteins on outer membrane

2. phagocytosis: “cell eating” cell engulfs large particles by wrapping outer membrane around them

3. autophogy: a cell’s internal recycling system that safely breaks down and digests own damaged parts or old organelles (recycles in lysosome)

trophic cascade

a phenom that happens when a keystone species is removed altering abundance of other species

aposematic coloring

when a toxic species is brightly colored to warn predators that they’re toxic

low fecundity

low birth rates but high survivorship

high fecundity

high birth rates but low survivorship

Allee effect

easier to find a mate because there’s more organisms. ONLY POSTIVE effect of high density

what’s harder to maintain, heat or cold?

heat because its harder to expel heat then it is to warm up

circadian

nitrogen fixation at night without photosynthesis