Scientific Method

1. Observation
2. Hypothesis
3. Experiment

protocol

description of steps in a scientific investigation

• materials and methods
• how you will measure
• timing
• data recording and presentng

Occam's Razor

if there are several explanations that fit an observation, the simplest is most probable and therefore best

Oscillatoria (in my picture,it's a little stringier)

Prokaryote

Cyanobacteria

colonial

Gleocapsa

Prokaryote

unicellular

cyanobacteria

notice: gelatinous sheath

Lactobacillus (yogurt)

Prokaryote

Microbe

Yeast

Eukaryote

Microbe

Prokaryotes

• unicellular
• lack membrane-bound organelles, including nucleus
• found in every habitat
• smallest cellular organisms
• most abundant organisms in world
• reproduction is mainly asexual
• feeding is mainly through absorption
• bacteria: 2 domains: bacteria and cyanobacteria

 Bacteria

• abundant in soil
• play role in nitrogen fixation
• decomposers
• Some are photosynthetic (but dont have chloroplasts)
• Some are chemosynthetic

3 structural groups of bacteria

1. Bacilli - rod shaped
2. Cocci - small spheres
3. Spirilla - corkscrew

nitrogen fixation

convert nitrogen from atmosphere into forms that can be used by plants  (bacteria)

decomposers

break down dead plants and animals, thus returning organic materials to system to be used again

chemosynthetic

obtain energy from oxidation of inorganic substances

cyanobacteria/blue-green algae

• photosynthetic
• contain chlorophyll a
• use water in process

Paramecium

Protist

Eukaryotic (has a nucleus)

movement: cilia

reproduction: sexual and asexual

Includes:

-oral groove

-food vacuole

-anal pore

-contractile vacuoles

-macronucleus

-micronucleus

*heterotrophic, live in freshwater environments

oral groove

paramecium

where fluids and foods enter cell

appears as a fold on one long side of the cell

cytopharynx

lower end of the oral groove

where food particles accumulate and food vacole is formed

food vacuole

envelops food particles and moves around cell

first it goes toward one end where digestive enzymes from lysosomes are secreted into vacuole

then it migrates to anal pore and releases waste

anal pore

where food vacuole goes to empty indigestible contents

contractile vacuoles

one at each end of paramecium

remove excess fluids from cell

macro and micronucleus

Macro - controls cell maintenance functions

Micro - responsible for genetic and reproductive functions, including creation of macronucleus

conjugation

2 cells exchange micronucleii and thus genetic material

each cell acts as both doner and recipient

Euglena

protist

photosynthetic but not entirely autotrophic

ability of phagocytosis

movement: flagellum (2, but only 1 visible)

Contains:

-Pellicile

-Flagellum

-Stigma

-Nucleus

-Contractile vacuole

-Chloroplasts

-Pyrenoids

Reproduction: asexual

phagocytosis

ability to surround and ingest food particles

pellicile

layer of elastic proteins just inside cell membrane

sort-of in place of cell wall, to keep it sturdy

flagellum

whip-like structures that emerge from canal or invagination

stigma

emerges just anterior to flagellum

aka "eyespot"

light-sensitive structure containing carotenoids

pyrenoids

associated with chloroplasts

organelle that stores sugars

Volvox

Protist

most complex rep. of blue-green algae, and largest colonies

movement: biflagellate

Contain:

-cytoplasmic strands

Reproduction: sexual and asexual (daughter colonies)

cytoplasmic strands

volvox

connect outer cells to one another

Endosymbiotic Theory

chloroplasts and mitochondria used to be individual prokaryotic cells that developed a symbiotic relationship with host cells

evidence: make their own energy and have their own DNA

Elodea

plant cell

contains:

-chloroplasts

-cell wall

-vacuoles

-nucleus

*Cytoplasmic streaming going on

cytoplasmic streaming

chloroplasts, which are suspended in cytoplasm, move throughout cell

much variation of rate and direction

Onion cell

eukaryotic

Plasmolysis

cellular shrinkage due to exposure to hypertonic solution (meaning solution is more condensed on outside)

Human epithelial cells

prominent nucleii

since they form a protective layer, they're tightly packed

amoeba

5 kingdoms of life

1. Monera
2. Protista
3. Fungi
4. Plantae
5. Animalia

Photosynthesis

(and where?)

H2O + CO2 ---(light)---> C(6)H(12)O(6) + O2

water + carbon dioxide ----> glucose and oxygen

Occurs in chloroplasts:

Photo = thylakoid membrane

Synthesis = stroma

photoreceptors

trap light energy in photosynthesis

Chlorophylls and different kinds

greenish pigments in all photosynthetic plant tissues

a - blue-green, in all photosynthetic things

b - olive-green, accesory pigment

c - only in certain types of algae

carotenoids

yellow, orange and red pigments

accesory pigments

coloring in reproductive parts (flowers/fruits)

2 groups:

carotenes (as in beta-carotene/vitamin A)

xanthophylls (yellow)

chromatography

Rf value: describing and distinguishing between pigments

polar or nonpolar?

Chromatogram:

Solvent front

b-carotene

xanthophyll

xanthophyll

chlorophyll a

chlorophyll b

origin

Rf value

distance substance travels from origin

________________________________

distance solvent travels from origin

*smaller distance traveled = smaller Rf

adsorb

to adhere to the surface of another compound without forming a chemical bond

on chromatography paper (which is polar), non-polar substances will adsorb, and therefore not move with the solvent

Hill Reaction

1937

Robert Hill showed that chloroplasts can operate in water in the presence of light and an electron acceptor to release oxygen

Implications

1. Oxygen had to come from water since no CO2 was present
2. Photo and synthesis are separate and can occur independently (because reactions giving up oxygen are different than those using CO2)
3. Oxidation-reduction reactions initiated by light are an integral part of photoysnthesis

reduced/oxidized

refers to NADP+ being reduced to NADPH as electrons race around during photosynthesis

DPIP

one way to detect process of reduction and oxidation

as DPID accepts electrons from reduction, the dye turns from blue to colorless

why is phosphate buffer added to tubes?

to keep pH steady so that chloroplasts don't die

photosynthetic rate

change in %T

____________

change in time