Standards:
A. Students know cells are enclosed within semipermeable membranes that regulate their interaction with
their surroundings.
Semiperable membranes are barriers surrounding a cell that allows certain substances to pass through
and not others. The words semipermeable membrane and selectively permeable membrane can be used interchangably. The
plasma membrane is a flexible boundary between a cell and its environment to allow a steady supply of nutrients regardless
of its external temperature. A plasma membrane regulates a semipermeables interaction with its surroundings.
Diffusion is the movement of a substance from an area of high concentration to an area of low concentration. There are
four types of diffusion: Simple diffusion: the movement of a substance from an area of high concentration to an area
of low concentration. So if there is more of a substance on the outside of a cell then some of that substance will enter the
cell through the pores in the plasma membrane. Facilitated diffusion: the process of diffusion in which molecules
diffuse across membranes with the help of transport proteins. Transport proteins are proteins that carry a substance from
one place and leave them in another. Bulky transport: there are two types of bulky transports 1. endocytosis:
when the cell takes a substance in and 2. exocytosis: when the cell pushes a substance out. the last type of diffusion
is active transport: the pumping of a substance across a cell membrane from a point of low concentration to a
point of higher concentration which requires energy. Osmosis is the same as diffusion except difffusion is only
water and osmosis is any other substance. Hypotonic:when there is more of one substance on the outside of the
cell than there is on the inside of the cell, which ties into diffusion. When this happens a cell explodes because the
pressure on the outside of the cell is to great. Hypertonic: when there is more of one substance on
the inside of a cell compared to that on the putside of the cell. When this happens the cell shrinks because there isnt
enough of the substance on the outside to balance out the cell. Isotonic: when the amount of a substance inside
the cell is equal to the amount of the substance on the outside of the cell. When this happens nothing happens
to the cell, its balanced.
B. Students know enzymes are proteins that catalyze biochemical reactions without altering the reaction
equilibrium and the activities of enzymes depend on the temperature, ionic conditions, and the pH of the surroundings.
Enzymes are biochemical catalysts. A catalyst is something that speeds up the chemical reaction
and goes into the reaction and comes out of the reaction unchanged. An equilibrium is when the rate of the forward reaction
is equal to the rate of the reverse reaction. So when it says, catalyze biochemical reactions without altering the reaction
equilibrium, it means that it speeds up both the forward reaction and the reverse reaction meaning its not changing
the equilibrium. The standard is also saying that if you change the temperature, ionic conditions, or the pH of a cell
you denature it. Changing the temperature, ionic conditions, and pH causes it to be denatured because if you change
the temperature you take the cell out of its natural enviroment which causes it not to function properly.
C. Students know how prokaryotic cells, eukaryotic cells (including those from plants and animals),
and viruses differ in complexity and general structure.
Prokaryotic cells lack a nucleus and a true outer membrane. Eukaryotic cells have a nucleus and
a true outer membrane. Eukaryotic cells have mitochondria, endoplasmic reticulum, and golgi apparatus while prokaryotic
cells don't. A prokaryotic cell lacks organelles while eukaryotic cells have organelles. Prokaryotic cells don't contain
bacteria. Protists, plants, animals, and fungi are all examples of eukaryotic cells. Fungui lives in the cells
of plants, animals, and bacteria.
D. Students know the central dogma of molecular biology outlines the flow of information from transcription
of ribonucleic acid (RNA) in the nucleus to translation of proteins on ribosomes in the cytoplasm.
In the central dogma of molecular biology RNA takes DNA to the ribosomes to make proteins. DNA contains all the
information needed. RNA is a messenger that takes the codes from DNA to the ribosomes where protein is made. Proteins
define characteristics. DNA is located in the nucleus of a cell. The ribosomes are located outside the nucleus.
Since DNA is in long strands it doesn't fit through the pores in the nucleus RNA squeezes through the pores and takes the
codes from the DNA to the ribosomes where proteins are made. The ribosomes need these codes to make the proteins.
The process in which the codes from DNA are taken to RNA is called transcripiton. The process in which RNA takes the
codes from DNA to the ribosomes in order for proteins to be made ussing the codes given by DNA is called translation.
Ribosomes are round particles that are composed of RNA and proteins that are found in the cytoplasm of living cells.
The ribosomes also serve as the site of assembly for polypeptides by messanger RNA.
E. Students know the role of the endoplasmic reticulum and Golgi apparatus in the secretion of proteins.
The endoplasmic reticulum is a system of membranes filling up most of the cytoplasm where lipids are
secreted and membrane-bound proteins are made. Secretion is the process of releasing chemicals from a cell.
The golgi apparatus is where proteins and lipids made in the endoplasmic reticulum are modified and sorted. The role
of the endoplasmic reticulum is to modify proteins, make macromolecules, and transfer substances throughout the cell.
So here is an example, when you buy a diamond does it always look just like it does when you bought it? The
answer is no. Someone had to go mine it out. So imagine you had this rough diamond mined from a cave. The
endoplasmic reticulum would take this rough diamond and start shaping it. During this process it would maybe only shape
the top half. Next it is sent to the golgi apparatus where the shaping process is finished. After this diamond
is made it has to be sent to the store for someone to buy it. This is when the protein leaves the cell.
Vesicles are used for the transportaion of materials within the cell membrane, between the cell mebrane and its
outside environment. The vesicles are part in my analagie when the diamond is packaged and sent to the store.
F. Students know usable energy is captured from sunlight by chloroplasts and is stored through the synthesis
of sugar from carbon dioxide.
Chloroplasts are the sites for photosynthesis and contain a lot of chlorophyll. Photosynthesis
is the process of using energy from sunlight to convert water and carbon dioxide into carbohydrates and oxygen. Chlorophyll
is green pigments in plants that help make the process of photosynthesis easier. Thylakoids make up the inner membranes
of a chloroplast. The Calvin cycle is a series of biochemical reactions during which carbon dioxide is reduced
into organic molecules which eventually form sugars. Light reactions are the part of photosynthesis in which light energy
is converted into chemical energy in the form of ATP. The stroma is a material of the chloroplasts containing enzymes
of the Calvin cycle. Pigments are large colored molecules that capture light energy and make it available for photosynthesis.
The chemical equation for photosynthesis is: energy(light)+H2O+CO2 which turns into C6H12O6+O2.
G. Students know the role of the mitochondria in making stored chemical-bond energy available to cells
by completing the breakdown of glucose to carbon dioxide.
Mitochondria is membrane-bound organelles in plant and animal cells that transform energy for the cell.
The inner fold of mitochondria is called cristae. It's purpose is to create many cites for chemiosmosis. Glycolysis
is the process in which sugars are converted to acids. Cellular respiration is the process in which a cell breaks down
sugar to release energy used for cellular work. The chemical equation for cellular respiration is C6H12O6+O2 turns into
CO2+H2O+energy in the form of ATP. I noticed that the chemical reaction for cellular respiration is the reverse reaction for
that of photosynthesis. The cytosol is the fluid portion of the cytoplasm outside of the organelles. The citric
acid cycle is a series of chemical reations that uses oxygen as a part of cellular respiration. Electron transport
chain is a group of electron carriers in mitochondria that transport electrons to and from each other in a sequence in
order to generate ATP. ATP is a source of energy.
H. Students know most macromolecules (polysaccharides, nucleic acids, proteins, lipids) in cells and
organisms are synthesized from a small collection of simple precursors.
Polysaccharides are a group of three or more molecules of sugar. Nucleic acids are the building
blocks of genetic material. Proteins are basic chemicals that make up the structure of cells and direct there activities.
Lipids are groups of chemicals that do not dissolve in water. The precursor of polysaccharides is sugar. The precursor
of proteins is amino acids. The precursor of lipids is. The precursor of nucleic acids is. Polymer is formed by
combining many smaller molecules in aregular pattern. Nucleotides are the building blocks for nucleic acids.
J. Students know how eukaryotic cells are given shape and internal organization by a cytoskeleton or
cell wall or both.
Cytoskeleton is the framework of a cell. A cell wall is the outer layer of a cell. Gap junctions
are the junctions between the plasma membranes of cells that allows communication between the cytoplasm of adjacent
cells. A desmosome is a cell structure specialized in cell-to-cell adhesion. Microfilaments are long thin fibers
in the cytoplasm.
I.Students know how chemiosmotic gradients in the mitochondria and chloroplast store energy for ATP
production.
Chemiosmosis is the coupling of hydrogen ions to the ATP production. Gradients are different amounts
of a given substance in given areas.
