0. Syllabus update: quiz tomorrow, microscope fun today  Do Now 12/1 OBJECTIVES: Observe & Identify cell structures found in prokaryotic and plant cells. TASKS: 0. Syllabus update: quiz tomorrow, microscope fun today  Classify the following organisms as prokaryotes or Eukaryotes: Apple tree, Duck, Mushroom, E. coli, Thermus aquaticus (a unicellular organism that lives in very hot water near deep-sea vents.)

Prokaryotes: Simple, yet Diverse Of the structures we have discussed, prokaryotes have ONLY: Cell membrane Ribosomes Flagella / cilia Cell wall*** Prokaryotes contain NO internal membrane structures

Prokaryotes are Small Prokaryotes are generally 10 to 100 times smaller than typical eukaryotic cells. Eukaryotic cells have specialized compartments where required materials can be kept, while prokaryotes must depend on diffusion to get materials throughout the cytoplasm where they need to be.

Many Prokaryotes Have Cell Walls Many prokaryotic cells have rigid cell walls for support and defense Most are made of a glycoprotein (amino acids + sugars) called peptidoglycan, very different from the cellulose-based cell walls of plants.

Prokaryotes are Very Diverse Biologists estimate that 98% of the different metabolic pathways in life occur in prokaryotes. In other words, if every single species of eukaryote went extinct, 98% of the reactions done by cells on Earth would remain. Prokaryotes have been found in EVERY terrestrial and aquatic ecosystem of Earth, without exception. Some prokaryotes can live in very difficult environments, from the Dead Sea to deep underground, to boiling hot springs.

Why 3 Domains? Differences between Bacteria And Archaea Although both are groups of unicellular prokaryotes, there are some crucial biochemical differences that make them distinct: Archaeans have unique membrane phospholipids Archaean ribosomes and other RNA molecules are more similar to eukaryotes than bacteria Archaean cell walls (if present) have different structures than bacteria or eukaryotes

Plant Cells Plants are multicellular eukaryotes, and typically contain the following parts that animal cells lack: Chloroplasts / plastids Large, central vacuoles Cell walls (cellulose)

Chloroplasts Absorb Light Energy… But NOT Green Light!

Free-living chloroplasts? Not quite… Cyanobacterium (prokaryote) Chloroplast (from eukaryotic plant cell)

Other Plastids

What else is so special about plant cells? Large, Central Vacuoles can take up most of The cell! It stores water, And some minerals

Anything Else? Yup – The Cell Wall SUPER IMPORTANT: Cell wall **not in animal cells** Structure: Hard outer covering made of cellulose fibers Function: provides support and strength to plant cells Think wood.

When you hear “Plant Cell Wall,” think Cellulose!

Fungi: The other Multicellular Heterotrophs Generally, fungal cells are more similar to animal cells than other cell types. The most important difference is the presence of cell walls made of chitin, a polysaccharide.

Fungal Diversity There is great variation in kingdom fungi, ranging from the smallest eukaryotes to the largest…

Recap: Prokaryotes (Superdomain) are small and simple: they contain NO internal organelles with membranes; everything happens right in the cytoplasm. Many have peptidoglycan cell walls. This group include domains bacteria and archaea. Plant cells (Kingdom Plantae) contain several unique features: chloroplasts, large vacuoles, and a cellulose cell wall. They are autotrophic, multicellular eukaryotes Fungi and Animal cells are similar in many ways, but the biggest distinction is that most fungi have chitin cell walls, which animals lack Protist cells are generally unicellular eukaryotes of great diversity

Phylogeny to know on The SATII 3 Domains vs. 5 kingdoms In the 5-kingdom system, prokaryotes of all types are in kingdom monera, which is divided into phylum bacteria and phylum archaea. 4 Eukaryotic Kingdoms (plant, animal, fungi, protist) 3 Domains (Modern) 5 kingdoms (traditional) Bacteria (Prok.) Monera (Bacteria + Archaea) Archaea (Prok.) Plantae Eukaryota Animalia Fungi Protista

Plant Phylogeny: 4 big groups Non-vascular seedless plants (bryophyta) Mosses, etc. Spore-formers Seedless vascular plants Incl. Pterophyta (ferns). Spore-formers Gymnosperms (flowerless seed plants) Incl. Coniferophyta (conifers w/ cones) ANGIOSPERMS (flowering plants) Monocots & dicots

Animal Phylogeny: “The Big 9” Phyla Animal Phyla: “Big 9” contain 95%+ of known animal species Porifera (sponges) Cnidaria (jellies) Platyhelmenthes (flatworms) Nematoda (roundworms) Annelida (segmented worms) Mollusca Arthropoda Echinodermata (starfish) Chordata (incl. vertebrates)

Kingdom Fungi Not much phylogeny to know for the SAT II here. Most are multicellular (exception = yeast) Heterotrophic, chitin cell walls Decomposers

Animal-like Protists: Protozoa Amoebas (phylum Rhizopoda) Sporozoans (phylum Apicomplexia): parasites Cilliates (phylum Ciliophora) incl. paramecia

Plant-like Protists: Algae May be unicellular or multicellular, but lack specialized tissues found in plants. Euglenoids (phylum Euglenaphyta): unicellular flagellates Brown Algae (phylum Phaeophyta): multicellular seaweed, incl. kelp Green Algae (phylum Chlorophyta): ancestors of land plants

Fungi-like Protists: Slime Molds Plasmodial slimes (phylum Myxomycota): single multinucleate cell, spore-former. Cellular slimes (phylum Acrasiomycota): congregation of amoeba-like protists, spore-former.

Notable Vertebrates Notable Classes & Superclasses in Phylum Chordata (All are in subphylum vertebrata – w/ backbones) Agnatha (jawless fish) Chondrichthyes (cartilaginous fish) Osteichthyes (bony fish) Amphibia Reptilia Aves (birds) Mammalia