The Nature of Living Things: How They Are Organized Chapter 2

Taxonomy of Living Things KingdomFeaturesExamples Monera Prokaryotic Unicellular Bacteria Protista Eukaryotes that “don’t fit into other kingdoms” Most are unicellular Amoeba, Algae, Slime Molds Fungi Filamentous eukaryotesYeast, Bread Mold Plantae Photosynthetic Multicellular Have cell walls Moss, Flowering plants, Conifers Animalia Multicellular Non-photosynthetic Coral, Insects, Mammals Next

Monera Table

Protists Table

Fungi Table

Plants Table

Animals Table

Levels of Organization Eukaryotic CellsProkaryotic Cells more complex contain a nucleus membrane-bound organelles protists, fungi, plants, and animals simple cells no nucleus no organelles bacteria

Eukaryotic Cells

Prokaryotic Cells

Eukaryotic Cells Structures OrganellesFunction Plasma membranePermeable cell membrane; separates external and internal environment NucleusContains DNA CytoplasmPart of the cell between the nucleus and plasma membrane; contains cytosol RibosomeSite of protein synthesis MitochondriaSite of aerobic respiration (ATP synthesis) ChloroplastContains chlorophyll; site for photosynthesis Cell wallBoundary outside cell membrane

Eukaryotic Nucleus

Cellular Molecules Small Organic MoleculesMacromolecules Occur free in solution in cytoplasm Examples: - Simple sugars - Fatty acids - Amino acids - Nucleotides Larger molecules Made of chains (polymers) of simpler/smaller molecules that act as building blocks (monomers) Examples: - Proteins - Nucleic acids - Polysaccharides

Small Organic Molecules Glucose Nucleotides

Macromolecules Smaller Organic Molecule or Monomers Macromolecule or Polymer

Macromolecules Amino Acids (Monomers) Proteins (Polymer)

Macromolecules Nucleotides (Monomers) Nucleic Acid (Polymer)

Proteins Long polymers made up of many monomers (amino acids) 20 different amino acids can combine in different number and sequence to produce huge variety of proteins Peptide bonds form between amino acids to form long chains, polypeptide chains

For example:

Function of Proteins Structural – help make up cells and cell membranes Catalysts (enzymes) or substrates (reactants) Help regulate production of other proteins tour/ tour/

Enzymes Group of proteins that catalyze chemical reactions

DNA Structure

Nucleotides join together to form long strands DNA consists of two strands Strands twist around each other to form a double helix Nucleotides are held together by a phosphodiester bond –Connects the sugar of one nucleotide to the phosphate of another Nucleotide sequence can vary Phosphodiester bonds

Polarity of DNA Each strand of nucleotides has a 5’ end and 3’ end –The 3’ end used to bond to another nucleotide –The 5’ end is attached to the phosphate group of the nucleotide A strand of DNA runs from the 5’ 3’ Each carbon in the deoxyribose is numbered 1’-5’

DNA Structure DNA consists of two strands joined together by hydrogen bonds between the base pair Base pairs are complementary on opposite strands –Adenine only base pairs with thymine –Guanine only base pairs with cytosine Two strands are considered antiparallel because the polarity of each strand opposite –Necessary for nitrogen bases to align and form hydrogen bonds

DNA Animations tour/ tour/ mations/content/DNA_structure.html mations/content/DNA_structure.html

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