Atoms combine to form molecules –E.g. Water is the most important to life Other organics …chemicals from C, H, O –Carbohydrates E.g. glucose, sucrose,

• Atoms combine to form molecules– E.g. Water is the most important to life

• Other organics …chemicals from C, H, O– Carbohydrates

• E.g. glucose, sucrose, fructose, maltose… (disaccharide of 2 glucose molecules)…simple carbs

• Starch: polysaccharides; for stored energy…complex carbs

• Can be structural– Chitin: exoskeleton of arthropods (insects,

crabs, spiders, etc)– Cellulose: gives plants and algae structural

fibers

– Proteins– Lipids– Fats

Proteins – have many roles

Made from 20 different amino acids monomers• Structural – hair, cell, cytoskeleton• Contractile – muscles, motile cells• Storage – sources of amino acids (egg whites)• Defense – antibodies, membrane proteins• Transport – hemoglobin, membrane proteins• Signaling – hormones, membrane proteins• Catalyst – free enzymes, membrane proteins

Lipids

• Fats, oils, waxes, steroids

• Polymers of fatty acids and glycerol

• Functions include:– Energy storage

molecules– Repel water– Prevent desiccation– Buoyancy– Thermal insulation

Different types of cells…Prokaryotes vs. Eukaryotes

• Simpler• Smaller size• DNA without nucleus• Cell wall & other crude

protective layers• Lack organelles

• Complex• >10x larger• DNA in nucleus• Cell membrane

– Some also have cell wall• Membrane bound

organelles– specialization

Nucleus

• Genetic control center• DNA

– Replicates during cellular division

– Genetic fibers = chromatin

• Sends instructions as RNA (in nucleolus) through pores – To synthesize proteins

(writes amino acid sequence)

Endoplasmic Reticulum

• Rough ER• Studded by ribosomes

– Assembles proteins (makes polypeptides) for further processing

• Membrane system– Continuous with

nuclear membrane• Creates compartments• Acts as highway or

conveyer belt

Smooth ER

• Continuous with Rough ER

• Lacks the ribosomes• Uses enzymes to make

lipids– In sex cells, SER makes

sex hormones– In liver cells, SER

detoxifies– In muscle cells, SER stores

and releases Calcium for muscle contraction

Golgi apparatus• Shipping / Receiving department

– Receives proteins from ER, modifies, packages, labels for destination, within or outside of cell

Lysosomes

• breakdown bodies• RER packaged

enzymes• Golgi modified• Digests:

– Food in vacuole– Bacteria in blood– Damaged organelle

(recycles)

Vacuoles

• Membranous sacks w/o digestive enzymes

• Carry food in

• Storage– Water– Chemicals– Waste– Pigments– Poisons

Contractile vacuoles

• Water regulation– When water continues

to seep inside• Osmotic properties and

differences in concentrations

– Pumps out excess– Prevents cells from

over-swelling or bursting

Chloroplasts

• Photosynthesis = converts solar E to glucose• Continuous double membrane/compartment

system– Fluid stroma– disks or grana = solar power packs

Mitochondria

• Converts glucose (stored E) into cellular E (ATP)– Potential E to chemical

E to Kinetic E– Via cellular respiration

• Double membrane & compartment system– Fluid matrix– Folds or Cristae to

increase Surface Area

Cellular balance: Diffusion…

• The green objects represent solutes

• Dashed line represents cell membrane

• Molecules in aqueous solution = solute

• Cell or plasma membrane• Passive transport;

Diffusion of solutes toward equilibrium

Osmoregulation = controlling water balance

• Isotonic: (iso = same) cell is in a solution of equal solute concentration• Hypotonic: (hypo = below) cell is in a solution of lower solutes• Hypertonic: (hyper = above) cell is in a solution of higher solutes

What about fish?

• Higher concentration of solutes outside– Water loss by osmosis– Drink water to

compensate– Excrete salts via gills

and more concentrated urine

• Higher concentration of solutes inside– Water gain by osmosis– Don’t drink the water

• Prevent swelling

– Excrete lots of dilute urine to compensate

Making sense of the vast Diversity of Life

…take into account the physical parameters– Geological– Environmental

& other characteristics and adaptations that separate groups of organisms from one another…

• Dealing with Temperature

• Various reproductive strategies

• Embryology and genetics

• Various morphology• Various feeding

strategies

• Most marine organisms are adapted to particular temperature ranges

• …some metabolize better in cold, some better in warm

– Enzymes; catalysts to many metabolic processes

• Ectothermic– Loses body heat to

environment• Endothermic

– Retains body heat• Poikilotherms

– Core temp. changes with environment

• Heterothermic

• Homoeothermic– core temperature relatively

constant.• Endothermic homeotherms

– physiological mechanism to maintain core temperature

– Mammals & most birds• Ectothermic homeotherms

– uses behavioral mechanisms to maintain homeostasis (constant internal environment).

• Endothermic heterotherms– Tuna & many sharks

poikilotherms?

Temperature & Salinity

Heat and salts (solutes) can flow in & out of organisms

Thus…

SA:V ratio is significant…size matters↓organisms = ↑ SA:V

e.g. In unicellular organisms much can passively diffuse

e.g. a whale loses little heat relative to body size

Fig. 4.17

Reproductive diversity• Asexual

– Clones (genetic copies)– Prokaryotic cells

• Binary fission– Simple, w/o nucleus

– Eukaryotic cells• Mitosis

– More complex, starts in nucleus

– Daughter cells– Budding (organismal)

• Sexual Reproduction• Adult typically diploid

– 2 sets of genetic info (2n)– Prokaryotes

• Plasmid Transformation, Conjugation

– Eukaryotes undergo Meiosis • 2n → 1n gametes

– Haploid sperm & egg

– Fusion of gametes• Fertilization

• Forms zygote (1n+1n=2n)

What is the advantage of sexual reproduction &

fertilization? • ↑ genetic diversity• Leads to variability in

ability…– Feeding– Predatory avoidance– Reproductive success

• Produce more offspring

– Favorable characteristics (best adapted to the environment)

• Passed on to next generation

• Become more common

Natural Selection– Survival of the

fittest

Evolution– Genetic change in

the population

4.21-4.22

We use all that information to help organize all of nature’s diversity

• Systematics; studying the diversity– Taxonomy to classify

organisms & groups

Fouling Community Fieldtrip• Meeting time: 1:45 pm, Feb 10, 2010 …rained option, will meet in class as

normal on 2/10… and push Fouling trip to 2/22

• Initial meeting site: South Shores Launch Ramp Next to Sea World Located on Mission Bay San Diego. Please try to carpool if possible.

• Directions: Interstate -5 exit Sea World Dr. West toward Sea World. Right at South Shore Launch Ramp.

– From Miramar: 163 S, 8 W, 5 N, 1st exit is Sea World/Fiesta Island, West toward Sea World. Right at South Shore Launch Ramp, meander through large parking areas to launch ramp and adjoining docks.

• What to bring: lab manual, pencil, non-dressy clothing; optional: snack, water, sunscreen, clipboard

• We will split into groups and collect samples from different locations in the harbor. We will measure turbidity, evaluate the plankton abundance and survey the fouling community at each location. All groups will gather at a central location and compare measurements and specimens.