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Substances that contain two or more elements in a fixed ratio.
-common compounds include:
NaCI (table salt) & H2O (water)
The sodium atom contains 11 electrons, 11 protons, and 12 neutrons. What is the mass number of sodium?
Is one in which the nucleus decays spontaneously, giving off particles and energy.
-have many uses in research and medicine
-can be used to determine the age of fossils and archeological artifacts.
-can be used to determine that fate of atoms in living organisms.
-are used in PET scans to diagnose heart disorders and some cancers.
-It is the inquiry-based effort to describe and explain nature.
- developed from our curiosity about ourselves and the world around us.
-one of biology's best demonstrated, most comprehensive, and longest-lasting theories.
-the unifying theme of biology.
-descent with modification
- a wide scale of size and
- a huge variety of life both past and present.
1. Order: Complex but ORDERED organization.
2. Regulation: The ability to REGULATE or adjust its INTERNAL environment (homestasis).
3. Growth & development: DNA controlled.
4. Energy processing: Take in energy via food items and emit it through activity & heat.
5. Response to the environment: Stimuli.
6. Reproduction: It's how life continues... individuals beget individuals of their kind (e.g., species).
7. Evolution: The capacity for populations to change (EVOLVE) over time (driven by mutations).
6. Organ Systems & Organs
10. Molecules & Atoms
Which of the following levels of life's hierarchy is not appropriate when referring to two of life's domains, Archae & Bacteria?
-nutrients are recycled but
- energy flows through.
- recycling of chemical nutrients and
- flow of energy.
-the smallest level of biological organization that can display all the characteristics of life.
-Is the level at which the properties of life emerge.
- are the lowest level of structure that can perform all the activities required for life.
- All organisms are made of
-The subunits that make up multicellular organisms such as humans and trees.
-All cells are enclosed by a membrane that regulates the passage of materials between the cell and its surroundings.
- Every cell uses DNA as its genetic information.
-simpler and usually smaller
-characteristic of bacteria
-subdivided by internal membranes into different functional compartments called organelles and
-found in plants & animals.
-is common to all organisms and
- consists of just four molecular building blocks with names that are abbreviates as A,G,C,T.
1. A (adenine)
2. G (guanine)
3. C (cytosine)
4. T (thymine)
The diversity of__includes about ___ species that biologist have identified and named.
-is the branch of biology that names and classifies species.
-it formalizes the hierarchical ordering of organisms into broader and broader groups.
Eukarya contains what kind of cells?
-Protists ( multiple kingdoms).
-are mostly decomposers
- digest dead organisms.
-The mechanism for descent with modification.
-Those individuals with heritable traits best suited for the local environment will reproduce with the greatest success.
-unequal reproduction success
- "Discovery science"
(mostly about descriving nature).
(mostly about explaining nature)
-verifiable observations and measurements to describe science.
-can stimulate us to ask questions and seek explanations and uses a process of inquiry called "scientific method".
-Much broader in scope than a hypothesis.
-Theories only become widely accepted in science if they are supported by an accumulation of extensive and varied evidence.
-are not the only way of "knowing nature".
1. Scientists build on what has been learned from earlier research.
- they pay close attention to comtemporary scientists working on the same problem.
2. Cooperation and competition characterize the scientific culture.
- Scientists check the conclusions of others by attempting to repeat experiments.
-Scientists are generally skeptics.
3. Science has two key features & measurements that others can verify and requires that ideas (hypothesis) are testable by experiments that others can repeat.
-New technologies advance science.
-Scientific discoveries lead to new technologies
H2O + SO3 = H2SO4 (sulfuric acid); a component of acid rain.
Is anything that occupies space and has mass.
Matter is found on Earth in three physical states:
Solid, Liquid, and Gas
Is a substance that cannot be broken down into other substances by chemical reactions
Are required in only very small amounts, but you cannot live without them.
-required in only very small amounts and are essential for life and health.
- for example, an iodine deficiency can cause "goiter", and flouring, added to dental products and drinking water, helps to maintain healthy teeth and bones.
-named from the Greek word "indivisible"
-is the smallest unit of matter that still retains the properties of an element
A subatomic particle with single unit of positive electrical charge (+)
A subatomic particle with a single negative charge (-)
-the only subatomic particle that has direct involvement in the chemical activity of an atom.
-orbits the nucleus of an atom in specific electron shells.
-the farther from the nucleus, the greater its energy.
-its number in the outermost shell determines the chemical properties of an atom.
Electrically neutral (has no charge)
The atom's central core
The number of protons in an atom
-A measure of the amount of material in an object
Is the sum of the number of protons and neutrons in its nucleus
Are forms of an element that differ in mass.
interactions usually in atoms staying close together, held by attractions
What are the 3 types of chemical bonds?
Ionic, covalent and hydrogen bonds
attraction between ions of opposite charge that holds them together to form a stable compound
-the strongest of the various bonds.
-Hold atoms together in a molecule
The number of covalent bonds an atom can form is equal to the number of additional electrons needed to fill its outer shell.
-has been validated by a huge number of observations and experiments.
Without a control group, you don't know if the experimental outcome is due to the variable you are trying to test or to some other variable.
-enable atoms to give up or acquire electrons, completing their outer shells.
-changes in the chemical composition matter
-includes reactants & products.
-can rearrange matter but cannot create or destroy matter.
one that is positively charged at one end and negatively charged at the other end
-one with an uneven distribution of charge.
*A weak bond between two molecules resulting from an electrostatic attraction between a proton in one molecule and an electronegative.
-give water an unusually high surface tension.
-the reason why water has a strong resistance to temperature change.
-the main reason why Earth is habitable
-cells are composed of 70-95% water.
-water molecules stick together as a result of hydrogen bonding.
-water has a strong resistance to change in temperature.
-frozen water floats
-water is a common solvent for life.
-molecules of the same kind stick together
-vital for the transport of water from the roots to the leaves of plants.
-The measure of how difficult it is to stretch or break the surface of a liquid.
-when water molecules get cold enough, they move apart, forming ice.
-a chunk of ice has fewer water molecules than an equal volume of liquid water.
-Ice floats because it is less dense than liquid water.
-if ice did not float, ponds, lakes, and even the oceans would freeze solid.
-life in water could not survive if bodies of water froze solid.
-are substances that resist pH change
-accept H+ ions when they are excess and
-donate H+ when they are depleted.
What is chemically nonsensical about this structure?
H--C == --H
-it has four electrons in an outer shell that holds eight electrons
-carbon can share its electrons with other atoms to form up to four covalent bonds.
-attach to other carbons and
-form an endless diversity of carbon skeletons varying in size and branching pattern.
-the simplest organic compounds
(ex. methane, a single carbon atom bonded to four hydrogen atoms)
-contain only carbon & hydrogen atoms
-its carbon skeleton and
-the atoms attached to the skeleton.
group of atoms that usually participate in chemical reactions
-ex. hydroxyl groups (-OH) and carboxyl groups (-COOH)
-links two monomers together and
-removes a molecule of water.
-link nucleotide monomers into long chains called "polynucleotides".
-form covalent bonds between the sugar of one nucleotide and the phosphate of the next, and
-form a sugar-phosphate backbone.
Nitrogenous bases hang off the sugar-phosphate backbone.
The reason why digestion breaks down macromolecule is_.
-breaks bonds between monomers
-adds a molecule of water, and
-reverses the dehydration reaction.
Include sugars and polymers of sugar. They include
-small sugar molecules in energy drinks and
-long starch molecules in spaghetti and French fries.
-a primary source of dietary energy and
-raw material for manufacturing other kinds of organic compounds.
-simple sugars that cannot be broken down by hydrolysis into smaller sugards and
-are the monomers of carbohydrates.
-are the main fuels for cellular work.
-form rings in water
-Glucose (in sport drinks) and
-Fructose (in fruits)
molecules that have the same molecular formula but different structures
(such as glucose & fructose).
-a double sugar
-constructed from two monosaccharides, and
-formed by dehydration reaction
("lactose" in milk, "maltose" in beer, malted milk shakes, and malted milk ball candy, and "sucrose" in table sugar)
-are complex carbohydrates
-made of long chains of sugar units-polymers of monosaccharides.
-is a familiar example of polysaccharide,
-is used by plant cells to store energy, and
-consists of long strings of glucose monomers.
(Potatoes & grains are major sources of starch in our diet)
-used by animals cells to store energy and
-converted to glucose when it is needed.
-is the most abundant organic compound on Earth
-forms cable-like fibrils in the walls that enclose plan cells, and
-cannot be broken apart by most animals.
-does not dissolve in water
-neither macromolecules nor polymers and
-hydrophobic (unable to mix with water).
-does not mix with water
-substances that do not dissolve in water
-joined with three fatty acid molecules,
-via a dehydration reaction.
-no double bonds and
-all three of its fatty acids saturated
-have a high proportion of saturated fatty acids,
-can easily stack, tending to be solid at room temperature, and
-contribute to "atherosclerosis", in which lipid containing plaques build up along the inside walls of blood vessels.
-high in unsaturated fatty acids and
-liquid at room temperature.
-converts unsaturated fats to saturated fats
-makes liquid fars solid at room temperature, and
-creates "trans fat".
are very different from fats in structure and function
-the carbon skeleton is bent to form four fused rings.
-a key component of cell membranes and
-the "base steroid" from which your body produces other steroids, such as estrogen and testosterone.
-are variants of testosterone
-mimic some of its effects
-can cause serious physical & mental problems
-may be prescribed to treat diseases such as cancer and AIDS, and
-are abused by athletes to enhance performance
-are polymers constructed from amino acid monomers,
-account for more than 50% of the dry weight of most cells,
-perform most of the tasks required for life, and
-form enzymes, chemicals that change the rate of a chemical reaction without being changed in the process.
-are macromolecules constructed from a common set of 20 kinds of amino acids.
-a carboxyl group (-COOH)
-an amino group (-NH2), and
-a hydrogen atom
-by dehydration reactions
-forming "peptide bonds", and
-creating long chains of amino acids called "polypeptides".
-one or more polypeptide chains,
-precisely twisted, folded, and coiled into a molecule of unique shape.
three levels of structure
-typically recognizes and binds to another molecule and
-enables the protein to carry out its specific function in a cell.
-mad cow disease, and
-provide the directions for building proteins, and
-include DNA & RNA.
1. a five-carbon sugar
2. a phosphate group, and
3. a nitrogen-containing base.
-A only pairs with T and
-G can only pair with C
-uses the sugar ribose and the base uracil (U) instead of thymine (T)
-both are polynucleotides
-both have same phosphate group along the backbone
-both usa A,C, and G bases
-DNA uses T while RNA uses U as a base
-Sugar differs between them
-DNA is double stranded while RNA is single stranded
-are the organelles of cellular respiration
-are found in almost all eukaryotic cells, and
-produce ATP from the energy of food molecules
-unique to the photosynthetic cells of plants and algae and
-the organelles that perform photosynthesis
-destroy harmful bacteria
-break down damaged organelles, and
-sculpt tissues during embryonic development, helping to form structures such as fingers.
-all living things are composed of cells and
-all cells come from other cells.
-Scanning electron microscopes (SEMs)
-Transmission electron microscopes (TEMs)
-older and usually smaller than eukaryotic cells
-simpler in structure
-lacks a nucleus
-its DNA is coiled into a nucleus-like region called the nucleoid
-fluid bec. molecules can move freely past one another
-mosaic bec. of the diversity of proteins in the membrane.
-are made of cellulose
-protect the cells
-maintain cell shape
-keep cells from absorbing too much water
-lack cell walls
-typically have an extracellular matrix
-helps hold cells together in tissues
-protects and supports them
-produces an enormous varietyof molecules,
-is connected to the nuclear envelope, and
-is composed of smooth and rough ER.
-directly by their membranes or
-by transfer of membrane segments between them
-lacks surface ribosomes
-produces lipids, including steroids, and
-helps livers cells detoxify circulating drugs
-works in partnership with the ER and
-receives, refines, stores, and distributes chemical products of the cell
__are large sacs or membrane that bud from the
-Golgi apparatus, or
-store organic nutrients
-absorb water, and
-may contain pigments or poisons
Cells require a continuous energy supply to perform the work of life.
Two organelles act as cellular power stations:
-the space between the two membranes,
-the stroma, and
-the space within grana
-A fold of the inner membrane of a mitochondrion
-Enzyme molecules embedded in cristae make ATP.
is a network of fibers extending throughout the cytoplasm.
-provides mechanical support to the cell and
-helps a cell maintain its shape
-provides anchorage and reinforcement for many organelles
-the protist Amoeba and
-some of our while blood cells
move in a coordinated bacck-and-forth
-shorter and more numerous than flagella
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