Domain II - Organisms EOCT REview

Energy in a Cell All life on Earth depends on the flow of energy The main source of energy is the Sun Energy from the sun is stored in nutrient molecules The energy is then released by the metabolism of living cells

ATP adenosine triphosphate Stores and releases the energy in its bonds when the cell needs it The energy is used to make new molecules, to build organelles and membranes, maintain homeostasis, to move (muscle cells), to transmit impulses (nerve cells) When a phosphate is added to an ADP (adenosine diphosphate), energy is stored When a phosphate is removed from an ATP, energy is released

ATP

Endergonic vs. Exergonic An endergonic reaction is any chemical reaction that stores energy Ex. photosynthesis An exergonic reaction is any chemical reaction that releases energy Ex. cellular respiration

Question #1 Compared to unicellular organisms, cells of multicellular organisms have fewer functions thicker membranes larger nuclei less variation

Photosynthesis Converts solar energy to chemical energy in the form of carbohydrates Done by autotrophs including plants, algae, and photosynthetic bacteria Takes place in the chloroplasts Equation: 6CO2 + 6H2O + energy from sunlight  C6H12O6 + 6O2

Chloroplasts thylakoids – saclike photosynthetic membranes grana – stacks of thylakoids stroma – space outside the thylakoids

Two Main Reactions: Light reactions – water is split, providing hydrogen and an energy source for the Calvin Cycle; oxygen is given off The ‘photo’ part of photosynthesis Also known as the light-dependent reactions Occurs in the thylakoids Calvin Cycle – series of reactions that form simple sugars using carbon dioxide and hydrogen The ‘synthesis’ part of photosynthesis Also known as the dark reactions or the light-independent reactions Occurs in the stroma

Photosynthesis

Cellular Respiration The carbohydrates produced by photosynthesis are used to produce ATP for life processes Done by all organisms Takes place in the mitochondria Equation: C6H12O6 + 6O2  6CO2 + 6H2O + ATP

Three Main Steps: Glycolysis – splitting the sugar, 2 ATP are produced Occurs in the cytoplasm Krebs Cycle – 2 ATP are produced, carbon dioxide is released Occurs in the mitochondria Electron Transport Chain – 32 ATP are produced, oxygen is used to make water

Cellular Respiration

Aerobic vs. Anaerobic Aerobic respiration – respiration that requires oxygen Anaerobic respiration – respiration that does not require oxgyen Lactic acid fermentation Alcoholic fermentation

ATP Cycle

Question #2 The complexity of body systems differs greatly among organisms. Which of the following organisms has developed organ systems for obtaining and utilizing energy? bacterium mushroom mouse virus

Classification Grouping of objects based on similarities Taxonomy – the branch of biology dealing with grouping and naming organisms Aristotle was the first to classify organisms Two groups: Plants – shrubs, herbs, or trees Animals – grouped based on where they live Carolus Linnaeus developed the system that is still used today He also developed the two word naming system – binomial nomenclature

Binomial Nomenclature The first word in the name identifies the genus and is always capitalized The second word, the species, is a descriptive word and is never capitalized Quercus alba – white oak (alba is Latin for ‘white’) Quercus rubra – red oak (rubra is Latin for ‘red’)

Levels of Classification Domain Bacteria, Archaea, Eukarya Kingdom Eubacteria, Archaebacteria, Protista, Fungi, Plantae, Animalia Phylum Class Order Family Genus Species

Kingdom Eubacteria ‘true bacteria’ Prokaryotes Cell walls with peptidoglycan Unicellular Autotrophs or heterotrophs Ex. Streptococcus pneumoniae, Escherichia coli

Kingdom Archaebacteria ‘ancient bacteria’ Prokaryotes Cell walls without peptidoglycan Unicellular Autotrophs or heterotrophs Ex. Methanogens, halophiles

Kingdom Protista Eukaryotes Some have cell walls made of cellulose Most are unicellular, some are colonial, some are multicellular Autotrophs or heterotrophs Ex. Amoeba, paramecium, algae, seaweed, slime molds

Kingdom Fungi Eukaryotes Cell walls made of chitin Most are multicellular; some are unicellular Heterotrophs Ex. Mushrooms, yeasts

Kingdom Plantae Eukaryotes Cell walls made of cellulose Multicellular Autotrophs Ex. Trees, mosses, ferns, flowering plants

Kingdom Animalia Eukaryotes No cell wall Multicellular Heterotrophs Ex. Sponges, worms, insects, fish, mammals

Viruses Are not classified because scientists cannot agree on whether or not they are living They reproduce (in a host) and contain DNA or RNA but are not made of cells Structure: DNA or RNA surrounded by a protein coat

Question #3 One main difference between members of the Kingdoms Plantae and Animalia is the ability to obtain energy reproduce move exchange gases

Question #4 The function of chlorophyll in a light reaction is to bind CO2 to H2O split to produce O2 trap light energy act as a source of CO2

Question #5 A group of prokaryotes that live in extreme environments are the viruses protists eubacteria archaebacteria

Flying insects, birds, bats Question #6 The table shows an early method of classifying animals. Which of the following best illustrates why the modern Linnaean classification system has replaced the system developed by Aristotle? Flying insects fly over both land and water. Eating habits of reptiles and some land mammals are different. Sea snake bones are similar to those of reptiles that live on land. Birds are warm-blooded like mammals. Group Air Dwellers Water Dwellers Land Dwellers Examples Flying insects, birds, bats Fish, whales, sea snakes Reptiles, land mammals

Question #7 Scientists have discovered a new species of animal. Which would provide the best basis for classifying this new species? DNA comparison diet of animal habitat of animal appearance of animal

Answers A C D

Information and images obtained from: http://www.doe.k12.ga.us/ci_testing.aspx?PageReq=CI_TESTING_EOCT&SubPageReq=GUIDES Google image search Campbell, Neil A. and Reece Jane B (2001). "6". Biology. Benjamin Cummings. Miller, Kenneth R. and Levine Joseph S. (2002). Biology. Prentice Hall.