Honors Bio Midterm

an organized way of gathering and analyzing evidence about the natural world

the heart of science; 5 steps: observing and asking questions, making inferences and forming hypotheses , conducting controlled experiments, collecting and analyzing data, drawing conclusions

a scientific explanation for a set of observations that can be tested in ways that support or reject it; when enough experimental data support a hypothesis, the hypothesis becomes a theory

1. all living things are made of cells

2. obtain and use materials and energy

3. grow, develop, and can reproduce

4. maintain a stable internal environment (homeostasis)

5. universal genetic code (DNA/RNA)

6. respond to the environment

7. evolve as a group (smallest group that can evolve is a population)

a group of the same species living in the same area

protons (+), neutrons (0), electrons (-)

the amount of protons in the nucleus

the weighted average of an elements isotopes

rounded atomic mass; protons + neutrons

atoms with the same amount of protons but different amount of neutrons

metal + nonmetal, electrons are TRANSFERRED (NaCl)

nonmetal + nonmetal, electrons are SHARED (H2O)

electrons in the outermost shell

occurs when valance electrons are SHARED by two atoms

electrons are shared EQUALLY between two atoms

a tendency to attract electrons of a covalent bond

one atom has greater electronegativity than the other, results in an UNEQUAL sharing of the electrons

bonds where two atoms attract valance electrons so unequally that the more electronegative atom steals the electron away from the less electronegative atom; an ion is the resulting charged atom or molecule

positive, metals, loses electrons (-), first in an ionic compound

negative, nonmetals, gains electrons (+), second in an ionic compound

relatively weak bonds that from between the partial positively charged hydrogen atom of one molecule and the strongly electronegative oxygen or nitrogen of another molecule; the key to all properties of water and what makes water so unique

shows the reactants which are the starting materials, an arrow to indicate their conversion into the products, the ending materials

an attraction between molecules of the same substance

an attraction between molecules of different substances

as water freezes, each molecule forms stable hydrogen bonds with its neighbors, holding them at “arms length” and creating a 3D crystal. ice crystals have fewer molecules than liquid water, therefore ice is less dense and floats on top of liquid water

a liquid consisting of a uniform mixture of two or more substances

the dissolving agent; water is the solvent of life

the substance that is dissolved

a solution in which water is the solvent, water’s versatility as a solvent results from the polarity of its molecules

measures the concentration pf hydrogen ions in a solution, the scale ranges from 0-14, pure water has a pH of 7

have pH values below 7

have pH values above 7

the study of compounds with bonds between carbon atoms; CHONP

monomers: monosaccharides, examples: glucose, fructose, cellulose, chitin, starch, functions: short term energy storage

monomers: amino acids, examples: enzymes, hormones, functions: structural support cell signaling and communication

monomers: triglycerides, examples: fats, oils, waxes, phospholipids, functions: long term insulation, membrane lipids

monomers: nucleotides, examples: DNA, RNA, functions: store and transmit genetic information

1665- Hooke discovers and names cells in thin slices of cork, 1676- Van Leeuwenhoek discovers protozoa by looking at pond water; first to see living cells under a microscope, 1831- Brown discovers and names the nucleus of the cell, 1838-39- Schleiden (plant) and Schwann (animal) theorize that all living things are made of cells, 1855- Virchow theorized that new cells are produced from existing cells

as the radius of a cell increases, its surface area increases as the square of its radius, but its volume increases as the cube of its radius (much more rapidly). therefore, as a cell increases in size, its surface area-to-volume ratio decreases

the microorganisms placed in domains Bacteria and Archaea consist of prokaryotic cells (prokaryotes); cells that do not have a nucleus but instead a nucleoid which is a region where the cell’s DNA is located (not enclosed by a membrane); prokaryotic cells are structurally simpler than eukaryotic cells

all other forms of life are placed in domain Eukarya (eukaryotes); these cells have a membrane enclosed nucleus, which houses most of their DNA, and many membrane bound organelles that perform specific functions

1. all things are made of cells

2. cell are the basic unit of structure and function in living things

3. new cells are produced from existing cells

small structures inside a cell that are surrounded by a membrane and have a specific function.

contains the cell’s genetic instructions encoded in DNA; serves as as the control center for cell metabolism and reproduction (ribosome factory)

if the nucleus is the command center, then ribosomes are the machines that carry out those commands. ribosomes are the cellular components that use instructions from the nucleus written in mRNA, to build proteins; sites of protein synthesis

the ER is an extensive network of flattened sacs and tubules, it is a prime example of the direct and indirect interrelatedness of parts of the endomembrane system; serves as a pathway for the transport of materials throughout the cell, also associated with synthesis and storage

outer surface lacks ribosomes; functions in a variety of metabolic processes; stores calcium ions

has bound ribosomes that stud the outer surface of the membrane ,appears rough,; many types of cell secrete proteins produced by ribosomes attached to rough ER, the rough ER is also involved with the production, folding, quality control and dispatch of some proteins

modifies, sorts, and ships cell products; the Golgi serves as a molecular warehouse and processing station for products manufactured by the ER

a membrane-enclosed sac of digestive enzymes, lysosomes have several types of digestive functions; also serve as recycling centers

large vesicles that have a variety of functions; fluid filled organelles enclosed by a membrane; contains stored food or wastes

the powerhouse of the cell; organelles that carry out cellular respiration in nearly all eukaryotic cells; mitochondria use O2 and release CO2 in transforming the chemical energy of foods to a form (ATP) that can be used for cellular work

site of photosynthesis; carries out complex multi-step processes; enclosed by an inner and outer membrane separated by a thin internal membrane space

hairlike structures with the capacity for movement

a long, hairlike structure used for movement; propel a cell through its liquid environment

gives the cell its shape and provides protection; not found in animal cells only plant

AKA plasma membrane, regulates what comes in and out of the cell; made up of the phospholipid bilayer

water attracting; the phospholipid head is hydrophilic

water repelling; the two phospholipid tails are hydrophobic

cells are able to recognize various molecules and other types of cells with the carbohydrate chains

helps transport materials (such as glucose) across the cell membrane

involved in cell to cell recognition

helps maintain the flexibility of the membrane

does not require energy; an example of passive transport is diffusion, the process by which particles move from an area of high concentration to an area of lower concentration

the movement of materials against a concentration difference; requires energy

the facilitated diffusion of water through a selectively permeable membrane

the process by which molecules that cannot directly diffuse across the membrane pass through special protein channels

(water leaves the cell) there is more M OUTSIDE the cell; plant cells: plasmolysis occurs, the plasma membrane pulls away from the cell wall,

animal cells: shrinks (losing water)

(water enters and leaves the cell equally)

plant cells: start to wilt

animal cells: normal

(water enters the cell) more M INSIDE the cell;

plant cell: normal (has turgor pressure)

animal cell: can burst, will swell (lysis)

used to express the concentration of a solution, how concentrated or diluted; moles of a solute over liters of a solution

molar

adenosine-triphosphate, made of of adenine, ribose a 5 carbon sugar, and 3 phosphate groups; ATP is the source of energy for use and storage in cells

a series of events (including mitosis) that take place in a cell as it grows and divides (end results= two identical daughter cells)

cell grows larger and makes proteins and organelles needed for DNA synthesis

DNA synthesis occurs, where DNA is copied

organelles and proteins necessary for cell division grow in preparation for mitosis

nuclear division (mitosis) occurs, followed by cytoplasmic division (cytokinesis)

prophase, anaphase, metaphase, telophase; NOT cytokinesis; PMAT

periods of growth between cell divisions (G1,S,G2)

DNA condenses from chromatin

chromosomes line up on the metaphase plate

sister chromatids move to opposite ends of the cell

nuclear membrane forms around chromosomes

separation of the cytoplasm, results in two identical cells

carbon dioxide + water --light→ glucose + oxygen

6CO2 + 6H2O --light→ C6H12O6 + 6O2

takes place in the chloroplast

light independent reactions(Calvin Cycle): do not require direct sunlight, take place outside the thylakoids, in the stroma; produce ADP and NADP+ and put it back into light dependent rxns

light dependent reactions: require direct sunlight, take place in the thylakoid membranes; produce ATP and NADPH

saclike chlorophyll-containing membranes

thylakoids that are interconnected and arranged in stacks

the fluid portion of the chloroplast, outside of the thylakoids

organisms that make their own food/energy; go through photosynthesis

organisms that cannot make their own food; dependent on autotrophs as an energy source

6O2 + C6H12O6 → 6CO2 + 6H2O + energy

oxygen + glucose → carbon dioxide + water + energy

photosynthesis put backwards is cellular respiration and vise versa; photosynthesis removes carbon dioxide from the air, and cellular respiration puts it back

pathways of cellular respiration that do not use oxygen

pathways of cellular respiration that require oxygen

glucose first enters a chemical pathway known as glycolysis, only about 10 percent of its energy is captured to produce ATP during this stage; occurs in the cytoplasm; enzymes split a molecule of glucose into two molecules of pyruvate, which releases energy that is transferred to ATP; 2 ATP molecules

energy stored in pyruvate is transferred to NADH and FADH2, and some 36 molecules ATP is produced with the help of glycolysis

energy is harnessed through a series of protein complexes embedded in the inner-membrane of mitochondria (called the electron transport chain and ATP synthase) to create ATP

the ATP molecule splits off one of its three phosphate groups, becoming ADP + a phosphate group