introduction - mr. curtis' biology site
TRANSCRIPT
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• 1.) Need food.
• 2.) Reproduce
• 3.) Use energy
• 4.) Grow and develop
• 5.) Maintain Homeostasis
• 6.) Have DNA
• 7.) Adapt & Respond to stimuli
• 8.) Made of at least one cell.
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• Homeostasis is an organism’s ability to regulate its internal environment.
• Example: – When your temperature goes up, you sweat to cool
yourself off. When you get cold, you shiver to warm up.
• Importance:
– Without being able to respond to changes in its internal environment, an organism would die.
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• 1.) Observation
• 2.) Hypothesis
• 3.) Prediction
• 4.) Experiment
• 5.) Data Collection
• 6.) Conclusion
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• Independent variable:
– is the variable being tested.
– is the variable the experimenter makes different between the different groups.
– is also called the manipulated variable.
• Dependent Variable:
– Is what changes because of the independent variable.
– Is what is measured in the experiment.
– Is called the responding variable.
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• Qualitative data: – Involves characteristics/descriptions.
– Ex: The plant’s leaves changed from green to yellow-brown.
• Quantitative data: – Involves numbers/calculations.
– Example: 25% of the plant’s leaves changed colors on the first day.
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Chart Summarizes data in rows/columns
Bar Graph Compares different data (magnitude)
Line Graph Shows how data changes over time
Circle Graph Shows how parts relate to the whole
Flowchart Shows order of steps
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• A.) All living things are made of cells.
• B.) Cells are the basic unit of structure and function in living organisms.
• C.) All cells come from existing cells.
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• Eukaryotes: – Have a nucleus
– Have membrane-bound organelles • E.R., Golgi, vesicles, lysosomes, mitochondria
– Some can be multicellular.
• Prokaryotes: – No nucleus
– No membrane-bound organelles • No E.R., No Golgi, No vesicles, No lysosomes, No mitochondria
– Only unicellular
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• Selectively Permiable:
– Only certain substances can cross the membrane and come into/go out of the cell.
– Substances that can cross freely:
• Water
• Amino acids
• Gases
• Sugars
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• A.) Receptor • A protein that serves as a receiving point for cellular
messages or signals.
• B.) Marker
• A protein that indicates the cell’s identity • Important in immunity
• C.) Channel
• A protein that serves as a doorway into the cell for large or electrically charged molecules.
6 Organelle Function Pro/Eu/Both Animal/Plant/Both
Nucleus Store & protect DNA; “control center of the
cell.”
EU
Both
Nuclear Envelope Controls what can go into/out of the nucleus
EU
Both
Ribosomes Make proteins Both Both
Mitochondria Make ATP EU Both
Chloroplast Make sugar EU Plants
6 continued E.R. Transport
proteins from ribosome to golgi; make lipids
EU
Both
Golgi Modify, package and ship proteins.
EU
Both
Cell Membrane Controls what can go into/out of the cell
Both Both
Cell Wall Provides shape and external support to the cell.
Both Plants
Cytoplasm Contains building blocks for molecules
Both Both
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• Diffusion – Movement of particles from high concentration to low.
• Facilitated Diffusion – Diffusion of large molecules using channel proteins.
• Osmosis – Movement of water from high concentration to low.
• Endocytosis – Active transport that brings large molecules into the cell by engulfing the molecule.
• Exocytosis – Active transport that sends molecules out of the cell.
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• Chemical reaction = results in new chemicals being formed.
• Physical reaction = changes the shape/structure of the molecules, but no new molecules are formed.
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• Reactants = on the left
• Products = on the right
• Example: CO2 + H20 + light Sugar + O2
REACTANTS PRODUCTS
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• Endothermic =
– absorbs energy.
– Photosynthesis is endothermic.
• Exothermic =
– Releases energy
– Cell respiration is exothermic
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• A.) pH changes • Can change the shape of the enzyme, resulting in it not
functioning.
• B.) Temperature changes
• Cold: molecules move slower, so are less likely to encounter enzymes.
• Hot: changes shape of enzyme • General rule: as the environment gets warmer, enzymes
work faster. HOWEVER, too hot = denatured enzyme.
• “Denature”: – Means: “Change the shape of an enzyme.”
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• Water has a slightly positive and slightly negative end.
– due to the unequal pull on the electrons by the molecules.
– Oxygen is “stronger” than hydrogen, so it can pull on the electron in the bond more.
– The electron is closer to the oxygen, so oxygen becomes negative and hydrogen becomes positive.
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• Your cells and the cells of all other organisms are made mostly of water.
• Water gives cells structure and transports substances within the organism.
• All cell processes take place in a watery environment.
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Macromolecule Function Monomer Example
Carbohydrate Provide energy Monosaccharide Glucose, sucrose, starch
Lipid Store energy, provide insulation, make cell membranes
No true monomer, but made of glycerol and 3 fatty acids.
Phospholipid, waxes, oils, fats
Protein Markers, channels, receptors, build bones and muscles, act as enzymes
Amino acids
Enzymes
Nucleic Acid Store and transmit heredity; contain information for making proteins
Nucleotide
DNA & RNA