Advanced Biology Midterm Review Holt Biology Chapters 1-6 Ch 1 Biology and You. Ch 2 Chemistry of Life Ch 3 Cell Structure Ch 4 Cells and Their Environment Ch 5 Photosynthesis and Cellular Respiration Ch 6 Chromosomes and Cell Reproduction Ch 1 Biology and You. Key Terms • Section 1 - Biology, Cell, Reproduction, Metabolism, Homeostasis, Gene, Heredity, Mutation, Evolution, Species, Natural selection, Ecology, • Section 2 – Genome, HIV, Cancer, Cystic Fibrosis, Gene Therapy • Section 3- Observation, hypothesis, prediction, pH, experiment, Control Group, independent variable, dependent variable, theory Biology – Study of Life All living things are made of cells. Cell are the smallest unit capable of life. Characteristics of All Living Things. 1. Cellular Organization 2. Reproduction 5. Heredity 3. Metabolism 6. Responsiveness 4. Homeostasis 7. Growth & Reproduction Steps of the Scientific Method • • • • Collect Observation Ask Questions Formulate Hypothesis and Make Predictions Experiment to confirm predictions - Collect and Analyze Data • Draw Conclusion and publish results. Hypothesis – A statement that can be tested by observation or experimentation. Theory – A set of hypothesis that have been tested and confirmed many times by many scientists. • Experimental Group – The group in the experiment that receives some type of treatment. • Control Group – The group in the experiment that receives no treatment. • Independent variable- The factor that is changed in the experiment • Dependent variable – The variable that is measured in the experiment. Ch 2 Chemistry of Life Key terms • Section 1 – Atom, Element, Compound, Molecule, Ion • Section 2 – Cohesion, Adhesion, Solution, Acid, Base • Section 3 Carbohydrate, Monosaccharide, Lipid, Protein, Amino Acid, Nucleic Acid, Nucleotide, DNA, RNA, ATP • Section 4 – Energy, Activation energy, Enzyme, Substrate, Active site Atom – Smallest unit of matter that cannot be broken down. Proton – Positive charge within nucleus Neutron – no charge within nucleus Electron – Negative charge – outside of nucleus. • Element- pure substance made of only one kind of atom. • Compound – a substance made of atoms of two or more elements • Molecule – Two or more atoms covalently bonded. • Covalent Bond – Sharing of electrons. • Hydrogen Bond – Electrostatic attraction between water molecules. • Ionic bond- An electrostatic attraction between molecules who have gained or lost electrons. Water Properties Cohesion Adhesion Capillary action Surface Tension pH H2O H+ + OH- Acid – form hydrogen ions when dissolved in water. pH < 7 Base – Form hydroxide ions when dissolved in water. pH > 7 Neutral – pH 7 Carbohydrates – organic compounds made of carbon, hydrogen and oxygen in a 1:2:1 ratio. Key source of energy found in fruits, vegetables and grains. Lipids include fats, phospholipids, steroids and waxes. Important in the structure and functioning of cell membranes. Proteins – Made of of amino acids. Found in meat. Many functions. •Enzymes promote chemical reactions. •Collagen found in skin, ligaments, tendons and bones. •Structural proteins found in hair, muscles and help blood clot. •Antibody proteins help defend against infection. •Hemoglobin carries oxygen. Nucleic Acids DNA – Stores hereditary information RNA – plays key role in the manufacture of proteins ATP – Energy storing molecule. Energy – ability to change matter. Activation energy – the energy needed to start a reaction. Enzymes lower activation energy. Ch 3 Cell Structure Key Terms • Section 1 – Light microscope, electron microscope, magnification, resolution, scanning tunneling microscope. • Section 2 – Cell theory, cell membrane, cytoplasm, cytoskeleton, ribosome, prokaryotic, cell wall, flagellum, eukaryote, nucleus, organelle, cilium, phospholipids, lipid bilayer. • Section 3 – Endoplasmic reticulum, vesicle, Golgi apparatus, lysosome, mitochondrion, chloroplast, central vacuole. Ocular lens x objective lens = total magnification Magnification – making image appear larger Resolution – clarity of image Cell Size – small cells function more efficiently than large cells. Cells need large surface to volume ratio. Cell Theory • All living things are made of cells. • Cells are the basic units of structure and function in organisms. • All Cells come from existing cells. Common Features of Cells Cell membrane Cytoplasm DNA Ribosomes Cytoskeleton No nucleus Lack membrane bound organelles. Circular DNA Cell wall surrounds membrane Nucleus containing DNA. Membrane bound organelles. Animal Cell Plant Cell Cell membranes are selectively permeable. Ch 4 Cells and Their Environment Key Terms • Section 1 – Passive transport, concentration gradient, equilibrium, diffusion, osmosis, hypertonic solution, hypotonic solution, isotonic solution, ion channel, carrier protein, facilitated diffusion. • Section 2- Active transport, sodium-potassium pump, endocytosis, exocytosis, receptor protein, second messenger. Passive Transport –does not require energy. Diffusion – The movement of a substance from an area of high concentration to an area of lower concentration until equilibrium is reached. Osmosis – The diffusion of water through a selectively permeable membrane. Diffusion through ion channels is passive transport. It does not require energy. Facilitated Diffusion is passive transport. It requires carrier proteins but it does not require energy. Why? Active Transport • The movement of a substance across the cell membrane against its concentration gradient. • The energy needed for active transport is supplied directly or indirectly by ATP. Active Transport An important carrier protein used to move substances against the concentration gradient. Active Transport Endocytosis Exocytosis Ch 5 Photosynthesis and Cellular Respiration Key Terms Section 1- Photosynthesis, autotroph, heterotroph, cellular respiration. Section 2 – Pigment, chlorophyll, carotenoid, thylakoid, electron transport chain, NADPH, carbon dioxide fixation, Calvin cycle. Section 3- Aerobic, anaerobic, glycolysis, NADH, Krebs cycle, FADH2, fermentation. Flow of energy • Energy flows from sunlight or inorganic substances to autotrophs then to heterotrophs. Photosynthesis Sunlight contains a mixture of wavelengths of visible light. Chlorophylls absorb mostly violet, blue, and red light, while carotenoids absorb mostly blue and green light. Pigment molecules are embedded in thylakoid membranes The electron transport chain converts light energy into chemical energy. Cellular Respiration Cellular respiration occurs in two stages. Glycolysis is the first stage of cellular respiration. Glucose is broken down in the cytoplasm. Glycolysis is an anaerobic process that breaks down one six carbon glucose to two three carbon pyruvate ions. Glycolysis uses two ATP molecules but produces four for a net gain of two ATP molecules. When oxygen is present, pyruvate produced during glycolysis enters a mitochondrion and Acetyl-CoA is formed and carbon dioxide is released. After the Krebs cycle, NADH and FADH2 contain energy that was previously stored in glucose and pyruvate. These electrons pass through the Electron Transport Chain in the inner membranes of the mitochondria. Most ATP is produced during aerobic respiration. When oxygen is not present, fermentation follows glycolysis regenerating NAD+ for glycolysis to continue. Ch 6 Chromosomes and Cell Reproduction Key Terms Section 1 – Gamete, binary fission, gene, chromosome, chromatid, centromere, homologous chromosome, diploid, haploid, zygote, autosome, sex chromosome, karyotype. Section 2 – Cell cycle, interphase, mitosis, cytokinesis, cancer. Section 3 - Spindle Prokaryotic Cells • Cell division is simple. • A single cell doubles in size and then separates into two daughter cells • Binary fission Eukaryotic Cell • Cell division more complex. • Process of cell division called mitosis. Chromosomes contain genetic information. After replication become visible by condensing. • Chromatids - one of the two strands of a chromosome that become visible during mitosis. • Centromere - the region of the chromosome that holds the two sister chromatids together during mitosis Chromatin - DNA and associated proteins observed when the nucleus in not dividing. Phases of the cell cycle. • G 1 - Most of the cell’s growth takes place. • S phase - chromosome replication takes place. • G 2 - preparation for cell division. • M phase (mitosis) - Cell division takes place. Cancer cells lose the normal ability to regulate the cell cycle. The Cell Cycle -Interphase • G 1, S, G 2, period between cell divisions. • The long strands of DNA and protein that make up chromosomes unfold and are difficult to see. • Chromosomes active directing cell growth & development. Mitosis - Prophase • Longest phase- 50% of mitosis. • Chromosomes appear as a result of condensing and coiling of chromatin. • Chromosomes consist of 2 identical strands attached at the centromere. Prophase • In animal cells two centrioles (b.) separate and move to opposite sides of the nucleus • Spindle fibers (c.) network of microtubules begin to form. • Nucleus begins to disappear. Metaphase • Shortest phase of mitosis - lasts only a few minutes. • Chromosomes complete attachment to spindle fibers • Chromosomes line up across the middle of cell Anaphase • Centromeres split, allowing sister chromatids to separate. • Chromosomes move to opposite poles. • Anaphase is complete when chromosomes have stopped moving. Telophase • Microtubules of the spindle begin to break apart • Chromosomes uncoil into chromatin • Nuclear membrane forms Cytokinesis • The division of the cytoplasm into 2 individual cells • Animal cells pinching • Plant cells - plate forms.