Bio 192 3$

all cells of more complex organisms require…

sufficient rates of exchange, and contact with the environment

* maintain internal homeostasis “steady state” in more variable environments

closed circulatory system

blood stays in vessels

interstitial fluid

within closed circulatory system

* fluid surrounding cells
* gases, nutrients, waste diffuse (or are pumped) between cells and fluids between fluid types

building block order

atoms

molecules

organelles

cells

tissue

organs

organ systems

organism

tissues

cells with similar structure and function

epithelial tissue

covers body, lines organs and body cavities

* can either be names for number of cell layers or cell shape

epithelial tissue subdivisions

simple

stratified

cuboidal

columnar

squamous

simple epithelial tissue

one layer

stratified epithelial tissue

multiple layers

cuboidal epithelial tissue

cube shaped

columnar epithelial tissue

column shaped

squamous epithelial tissue

squished

connective tissue

mix of cells and extracellular matrix

* matrix can be liquid, protein, minerals, or a combination

connective tissue subdivisons

loose connective tissue

fibrous connective tissue

blood

adipose tissue

bone

cartilage

loose connective tissue

joins tissue, holds organs in place

fibrous connective tissue

tendons- connect muscle to bone

ligaments- connect bone to bone

blood connective tissue

matrix is plasma- water, salts, dissolved protein

adipose tissue

insulation and energy

bone connective tissue

matrix of calcium phosphate

cartilage connective tissue

strong, supoport

muscle tissue

largely actin and myosin protein

muscle tissue subdivisons

skeletal

smooth

cardiac

skeletal muscle

striated (stripes) voluntary body movement and diaphragm

smooth muscle

lacks striation. used for involuntary organ movement

cardiac muscle

striated heart muscle - pumps blood

nervous tissue

send, receive, and process signals

nervous tissue subdivisons

neurons

glia

neurons

transmit signsls

glia

support cells; nourish, insulate, and replenish neurons

feedback mechanisms help maintain

homeostasis

negative feedback

response reduces the stimulus

negative feedback overview

more typical type of feedback

stimulus: increased temperature - response: sweating

stimulus: low blood sugar - response: hunger

positive feedback

response amplifies the stimulus

positive feedback overview

stimulus: pressure during childbirth - response: contractions

circadian rhythm

physiological changes cycling roughly every 24 hours

* occurs in plants and animals

thermoregulation

maintain internal body temp

thermoregulation overview

temp affects diffusion rates, membrane fluidity, enzyme activity

* warming or cooling by 10 c can increase or decrease enzyme activity by a factor of 2
* two warm can denature enzymes (nonfunctional)

species can vary in optimal temperature

endothermic

heat primarily through metabolism (internal)

ex mammals, birds, some non-avian reptiles, some fish, many insects

ectothermic

heat primarily gained from environment

ex amphibians, lizards, snakes, turtles, many fish, most interebrates

homeotherm

temp is relatively consistent

poikilotherm

temp varies with environment

energy … nutrients …

flows

cycle

heat exchange

heat moves from object with higher temp to the object with lower temp

radiation

electromagnetic waves

evaporation

cooling from liquid to gas

convection

transfer from air or liquid passing a surface

conduction

direct transfer between objects

insulation

skin, hair, fat, feathers

circulatory system

vasodilation

vasoconstriction

countercurrent exchange

vasodilation

expands blood vessels

vasoconstriction

shrinks blood vessels

countercurrent exchange

transfer heat between blood flowing in opposite directions

torpor

short term slowing of metabolism in response to extreme heat, cold, or inadequate food

* generally occurs in smaller organisms
* hummingbirds nighttime temperature can drop by 25C

hibernation

long term torpor from cold/ reduced food

* body temperature can cool near freezing (0C)

estivation

torpor in response to hot, dry conditions

metabolic diversity

autotroph

heterotroph

mixotroph

autotroph

self nourished

inorganic carbon source

heterotroph

other nourished

organic carbon source

chemoheterotroph

an organism that obtains energy by breaking down organic compounds produced by other organisms through cellular respiration

obligate aerobe

organism cant survive without oxygen

facultative anaerobe

use O2 if its available but can use other e- acceptors

obligate anaerobes

poisoned by O2

energy and nutrients in prokaryotes

can be obligate anaerobes, facultative anaerobe, or obligate aerobe

plasma membrane infolding can function like mitochondrial cristae or chloroplast thylakoids

nutrient uptake through membrane

* cell wall restricts endocytosis

prokaryotes can be…

autotrophs, heterotrophs, mixotrophs

parasitic or free living

mutualistic or commensal

prokaryotes are..

major players in nutrient cycling

* fixing nitrogen- atmospheric N2 biologically available as NH3
* mineralization
* remove atmospheric CO2 (C-sequestration) and produce O2

mineralization

decompose organic matter to inorganic form

energy and nutrients in protists

* protists have important ecosystem roles
* most obligate aerobes, some anaerobic
* plankton- small, suspended protists and bacteria- base of aquatic food webs
* oomycetes- decomposers and parasitic- cause of Irish potato famine
* many protists are mixotrophs

color of photoautotrophic protist vary with…

depth and pigments

1/2 of all photosynthetic activity is from..

protists (30%) and prokaryotes (20%)

protist diversity

some protists can cause human disease

* trypanosoma

energy and nutrients in plants

most plants are photosynthetic autotrophs and all are obligate aerobes

carnivorous plants

generally grow in poor soils

are photosynthetic but supplement nutrition with animals, digested with enzymes

epiphytes

photosynthetic but grow on other plants as commensals

* water and minerals come from air/ rain

parasitic plants

on plants or mycorrhizae

photosynthesis equaiton

6CO2 + 6 H20 > C6H12O6 + 6O2

photosynthesis

accomplished by leaves- energy and gas exchange

stomata

pores for gas exchange and transpiration

* have guard cells

guard cells

open and close each stoma through osmosis

mesophyll

middle of leaf

palisade layer

tightly packed elongated cells

spongy layer

below palisade, loosely packed cells with greater air space

vascular tissue

xylem,phloem

roots

access water and minerals

leaf size

affects light absorption, heat, transpiration of water

phyllotaxy

leaf arrangement

optimize plants absorbance and leafs efficiency

too dense- shaded leaves respire more than photosynthesize- shed by pruning

leaf orientation

horizontal vs vertical

too high of light intensity can damage leaves

height and branching

balance energy demands and resource availability

fungi

unicellular and multicellular

most are obligate aerobes

absorb nutrients following external enzymatic digestion

function as decomposers, parasites, mutualists

decomposers

break down organic waste into available mineral nutrients

able to digest lignin and cellulose in wood

specialized hyphae

trapping prey

haustoria

specialized hyphae

exchanging nutrients with plant cells

mycorrhizae

specialized hyphae

mutualism with plant roots- sugars for minerals

* ectomycorrhizal
* arbuscular

ectomycorrhizal

hyphae remain outside plant cells

arbuscular

penetrate plant cell wall

endophytes

fungi living among plant cells

* can produce toxins to deter herbivores, medicines
* help digest plant material in guts of some herbivores

leaf cutter ants

deliver leaves to “farmed” fungi to digest

* fungi produce proteins and carbs to feed ants

lichens

fungi symbiotic with photosynthetic algae or cyanobacteria

pathogens

modify ant behavior

* diseases of many trees and food crops
* aflatoxins from fungi on peanuts and grains
* athletes foot and ringworm on skin

animals

aerobic chemoheterotrophs

obtain food by ingestion and digest internally

herbivores

consume plants/ algae