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58 Cards in this Set
- Front
- Back
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What is Biology? |
"the study of life" |
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A single teaspoon of soil can contain up to 1 billion microorganisms. |
Fungi, bacteria, protozoa, nematodes |
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How much bacteria are there in the world? |
There are more bacteria on your skin than there are people on the planet. |
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How do we define life? |
Living organisms possess all or most of the following.... Organization, Acquisition of materials, and energy, Metabolism, Response to stimuli, Reproduction, Growth, and Adaptation. |
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What is the basic unit of matter? |
An atom (together they form molecules H2O) |
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What is the most basic unit of life? |
The cell (composed of molecules) |
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Memorize... |
Similar cells together form tissues Similar tissues together form organs Organs work together in organ systems Organ systems form an organism |
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Homeostasis |
To sustain this order, life must typically maintain particular internal conditions (Regulating temp, pH. |
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Acquisition of Materials and Energy |
Organisms must obtain materials from their environment to produce energy needed at the cellular level. (easy to see in a food web) |
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Metabolism |
Required in order to sustain life. The set of chemical reactions involved in the conversion of the food you eat into the molecules needed to provide you with energy. Necessary for homeostasis, response to environment, reproduction, and growth. |
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Response to the Environment |
Organisms can alter their physiology or behavior based on a changing environment. |
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Reproduction |
The ability to produce new individual organisms, either asexually from a single parent organism, or sexually from two parent organisms. |
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Growth |
Maintenance of a higher rate of anabolism (building up) than catabolism (breaking down). A growing organism increases in size in all of its parts, rather than simply accumulating matter. |
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Mitosis |
Cellular differentiation and apoptosis we go from a single cell to a multi cellular organism. |
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Adaptation |
Makes an organism better suited for its environment at a certain point in time. Increases and organisms ability to survive in that specific environment. The organisms with the adaptation survive and reproduce, thereby passing on their genes to offspring |
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What does life require? |
All living organisms are composed of cells and require liquid water. |
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Why is the earth so blue? |
Water covers 70.9% of the earth's surface. Water makes up between 55-78% of a human's body weight. |
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Why is water important to life? |
Water has special chemical properties that make it ideal for life. |
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Life sustaining properties: Unique Chemical Properties That Make Water Ideal for Life |
Polar, Solid less dense than liquid, High thermal capacity, Cohesion/Adhesion, Dissolves many substances. |
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Importance: Unique Chemical Properties That Make Water Ideal for Life |
Hydrogen bonds, Ice floats, Moderates temps on earth and in organisms, Capillary actions, Facilitates chemical reactions. |
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Polar |
Water is a polar molecule Oxygen side is slightly negative (because it is more electronegative than hydrogen) Hydrogen side is slightly positive |
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Nonpolar |
Molecules without a directional charge |
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Water is polar |
Molecules constantly body to each other (positive on one side (H), negative on the other (O) |
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Hydrogen bond |
The weak attraction between the hydrogen atom of one water molecule and the oxygen atom of another |
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Why is water unusual? |
Because it is less dense as a solid than as a liquid. (water expands due to hydrogen bonding) Ice is 10% less dense than water at 4 degrees Celsius |
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What would happen if ice sank? |
All water on earth would freeze solid. |
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Moderates temps on earth and in organisms |
Mercury Day temp 420C 778F Night temp -220C -364F Mars Day temp 110C 230F Night temp -150C -240F Earth Day temp 25.9C 78.5F Night temp 21.9C 71.3F |
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Cohesion |
The tendency of like molecules to stick together |
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Adhesion |
The tendency of unlike molecules to stick together (such as water hydrogen bonding to other polar molecules) |
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Cohesion/Adhesion |
Draw water against gravity into the stem of the plant (capillary action) Ex: plant transpiration |
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What makes a good solvent? |
Water |
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Hydrophilic |
The compound is able to dissolve in water (sugar, salt) |
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Hydrophobic |
The compound can't dissolve in water. (fats, oils) |
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Water can dissolve.... |
Acids and Bases |
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pH scale |
Measure of the relative amounts of acids and bases in a solution pH greater than 7=basic pH lower than 7=acidic Pure water=7 (neutral) |
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What is the pH of cells to stay healthy? |
6-8 |
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All Earth's organisms..... |
Are composed of cells, can maintain homeostasis, can evolve, require liquid water, and have a common set of biological molecules. |
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What are four biological molecules? |
Carbohydrates, proteins, lipids, and nucleic acids. |
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Carbohydrates |
Major source of energy for cells. Molecules of carbon, oxygen, and hydrogen. |
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Monosaccharides |
Simple sugars are building blocks for carbs. |
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Disaccharides |
Are composed of two monosaccharides. |
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Polysaccharides |
Are composed of many monosaccharides. |
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Proteins |
Chains of amino acids; joined by peptide bonds. Some proteins are involved in carrying out chemical reactions(enzymes) while some have a structural role. Makes up at least half of the dry weight of most cells. There are 20 different amino acids, with different amino acids, with different chemical properties |
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Lipids |
Hydrophobic; composed mostly of carbon and hydrogen. |
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What are the three types of lipids? |
Fats (composed of a glycerol molecule joined with 3 fatty acid tails) Steroids (4 carbon rings with cholesterol, estrogen, and testosterone) Phospholipids (composed of a glycerol molecule, 2 fatty acid tails and a phosphate group) |
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Nucleic acids |
Composed of nucleotides (sugar+ a phosphate+ a nitrogenous base. |
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What are nucleotides two types? |
DNA and RNA depending on the sugar. |
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DNA |
Is the hereditary material in nearly all organisms with a double helix. |
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Base-pairing rules |
Bonding between bases on opposite strands. A with T (DNA only) A with U (RNA only) G with C (DNA and RNA) Each strand consists of a sugar-phosphate backbone |
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All cells on Earth are.... |
Prokaryotic or eukaryotic |
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Similarities of Prokaryotic and Eukaryotic cells |
A cell membrane (phospholipids and proteins) Cytoplasm (gelatinous aqueous interior) Ribosomes (complex of RNA and protein that carry out protein synthesis) DNA (as a molecule of heredity) |
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Difference of Eukaryotic Cells |
larger, more complex, have a true nucleus, and organelles |
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Advantage of Eukaryote |
incompatible reactions can be separated |
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All cells are surrounded by.... |
a plasma membrane |
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Plasma Membrane |
Made of phospholipids bilayer: hydrophobic tails orient inside the membrane Fluid mosaic: lipids and proteins can move about within the membrane Semipermeable: some molecules can cross and some can't |
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Natural selection |
based on variations in organisms that may increase or decrease survival |
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All earth's organisms share similarities |
Same basic biochemistry, with same types of macromolecules. All organisms consist of cells Cells always have phospholipids bilayermembrane Eukaryotes share most of the same organelles |
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The tree of life and evolutionary theory |
This unity of life explained by tree of life with modern species have evolved from common ancestory |
