academic biology: midterm review -...
TRANSCRIPT
Chapter 1: The Science of Biology
• Biology – the study of the living world
• Scientific Method• Step 1: Observation
• Step 2: Forming a Question
• Step 3: Form a Hypothesis (suggested answer based on evidence)
• Step 4: Experiment & Compile Data (should only test ONE variable
• Step 5: Analyze Data
• Step 6: Draw Conclusion & Retest as needed
Chapter 1: The Science of Biology
• Independent Variable• The variable the scientist changes
• Dependent Variable• The variable being measured
• Use the metric system
• When enough experimental data support a hypothesis, it can become a theory.• Theories change!
Chapter 1: The Science of Biology
• 8 Characteristics of Living Things:1. Made up of cells (smallest unit of life)
2. Reproduce (sexually or asexually)
3. Based on universal genetic code (DNA)
4. Grow & develop
5. Obtain & use materials/energy (metabolism)
6. Respond to their environment (stimuli)
7. Maintain stable internal environment (homeostasis)
8. Change over time (evolution)
Chapter 1: The Science of Biology
• Tools for Observing Life:• Compound Light Microscope – to observe small, living
samples
• Electron Microscope – higher magnification, but can only observe dead, properly preserved/prepared samples
• Robert Hooke coined the term “cell” looking at cork through a simple light microscope
Chapter 2: The Chemistry of Life
• 4 Main Organic (Carbon) Compounds:• Carbohydrates
• Main source of energy
• Made up of monosaccharides (sugars)
• Proteins• Control reaction rates, allow molecules in and out
of cells, fight disease, make up muscles
• Made up of amino acids
Chapter 2: The Chemistry of Life
• 4 Main Organic (Carbon) Compounds:• Lipids
• Comprise membranes, energy storage, insulation
• Made up of glycerol & fatty acids
• Nucleic Acids• Store and transmit genetic information
• Made up of nucleotides (sugar, phosphate group & nitrogenous base)
Chapter 2: The Chemistry of Life
• Chemical Reactions – rearranging of atoms to form new compounds• Activation Energy – E needed to start a rxn
• Catalyst – speeds up the rate of chemical reactions• Enzymes – naturally occurring, biological
catalysts; lower activation E needed• Can only be used to speed up ONE specific
reaction!!!
Chapter 2: The Chemistry of Life
• Water• Polarity
• H’s and O don’t share e-’s evenly
• O side ends up slightly negative; H side is slightly positive
• Universal solvent
• Ice floats!
• Most abundant compound in living things
• Hydrophilic – water loving
• Hydrophobic – water fearing
Early Earth
• The Universe • Formed by Big Bang
• 14 BYA
• The Earth• Formed 4.6 BYA
• First organisms were probably bacteria (archaebacteria)
• Reducing atmosphere oxidizing atmosphere• Cyanobacteria released O2
Early Earth
• Miller & Urey• Recreated hypothesized conditions of early
Earth in lab• Demonstrated how organic molecules could
have formed before life was present
Chapter 16: Darwin’s Theory of Evolution
• Evolution by Natural Selection – species change over time• Struggle for Existence
• Survival of the Fittest
• Natural Selection
• Evidence of Common Ancestry:• Structural similarities (body parts), similar genes,
similar species in geographically isolated areas
Chapter 16: Darwin’s Theory of Evolution
• Published The Origin of Species• Controversial for its time
• Fossil Record – collection of fossils over time that illustrates ancestry commonalities between species• Shows that most organisms that have ever lived
on Earth are extinct!
Chapter 7: Cell Structure & Function• In multicellular organisms, cells specialize to
perform different functions.
• Cell Theory:1. All living things are made of cells.
2. Cells are the basic unit of life.
3. All cells are produced by existing cells.
Chapter 7: Cell Structure & Function
• Prokaryotic Cells – lack “true” nucleus and membrane-bound organelles (bacteria)
• Eukaryotic Cells – contain a membrane-bound nucleus as well as specialized organelles • Plant Cell – square-ish; cell wall, large central vacuole,
chloroplasts & general organelles
• Animal Cell – round-ish; centrioles & general organelles
(Do you remember the functions of each organelle?)
Chapter 7: Cell Structure & Function
• Endosymbiotic theory• Proposed by Lynn Margulis
• Bigger prokaryotes engulphed smaller prokaryotes organelles
• 3 endosymbionts: chloroplast, mitchondria, and centrioles
• Fluid Mosaic Model of the Cell Membrane:• Phospholipids – main component
• Proteins channels and pumps – made from proteins; aid materials in movement across cell membrane
• Cell Transport:• Passive transport
• Diffusion – movement from an area of high concentration to an area of low concentration
• Osmosis – movement of water from an area of high concentration to an area of low concentration
• Facilitated Diffusion – Diffusion that gets “help” from a protein
• Active Transport• Movement from LOW to HIGH concentration
• Requires energy
• Endocytosis: Pino- and phagocytosis
• Exocytosis
• Water movement• Hypertonic – water out; cell shrinks
• Hypotonic – water in; cell may burst
• Isotonic – water in and out; cell’s happy!
Energy Transfers & ATP
• ATP ADP + Pi + E
• Energy is released when the bond holding the end phosphate is broken
Energy Pyramid
4° con.E 3° consumer
2° consumer1° consumer1° producer
% E/g decreases as you go up because efficiency in E transfer is not 100%
E is lost - Metabolism, waste, cellular processes
Chapter 8: Photosynthesis
• 6CO2 + 6H2O + Sunlight C6H12O6 + 6O2
• Occurs in the chloroplast• Thylakoid: membrane sacs; Chlorophyll (pigment)
found in membranes (reflects green light)• Light-Dependent Reactions – produce high-energy
molecules (ATP & NADPH)
• Stroma: fluid surrounding thylakoid• Calvin Cycle (Light-Independent Reactions) – produce
high-energy sugars
Chapter 9: Cellular Respiration
• 6O2 + C6H12O6 6CO2 + 6H2O + 36 ATP
• 2 Types:
• Aerobic
• Anaerobic
Chapter 9: Cellular Respiration
• Steps of Aerobic Respiration
• Glycolysis – occurs in cytoplasm, net gain 2 ATP, anaerobic (no O2 needed), if O2 is present followed by Krebs Cycle
• Krebs Cycle - occurs in matrix (inner cavity of mitochondria), aerobic (O2 needed), net gain 0 ATP
• Electron Transport Chain – occurs in cristae (mitochondria), aerobic (O2 needed as the final electron acceptor), net gain 34 ATP
Chapter 9: Cellular Respiration
• Fermentation• Alcoholic Fermentation
• Lactic Acid Fermentation – causes muscle soreness during excessive physical activity
• Sources of Energy:• Stored ATP (energy is released as bonds are broken and
phosphate groups are removed from ATP)
• Cellular Respiration
• Lactic Acid Fermentation