AP Biology Cheat Sheet (DRAFT) by MariZL

Eukaryotic cells have internal membranes that compar­tme­ntalize their functions
Comparing prokar­yotic and eukaryotic cells
Since prokar­yotic cells lack a membra­ne-­bound nucleus, eukaryotic cells are the main difference between these two types of creatures. Eukaryotes store their genetic material in their nuclei.
Prokar­yotic cells
Lack nuclei and other membra­ne-­enc­losed organelles
Only organism is of the domains
Bacteria and Archaea consist of No Nucleus
No membra­ne-­bound organelles
Nucleo­id-DNA in an unbound region
Cytopl­asm­-Bound by the plasma membrane.
Eukaryotic cells
have internal membranes that compar­tme­ntalize cellular functions
Protists, fungi, animals, and plants all consist
-DNA in a nucleus that is bounded by a membranous nuclear envelope
membra­ne-­bound organelles
cytoplasm in the region between the plasma membrane
are generally much larger than prokar­yotic cells
A panoramic view of eukaryotic cell
has internal membranes that partition the cell into organelles
plant and animal cells have most of the same organelles

Catalysts
Proteins provide the primary function of enzymes, which are catalysts that quicken practi­cally all chemical events within cells. Although some biological reactions can be catalyzed by RNAs, proteins are respon­sible for the majority of them.
Amino acid monomers
Defini­tion: The monomers that make up proteins are amino acids. A protein is made up of one or more polype­ptides, which are individual linear chains of amino acids.

Alpha carbon
The link between the amino group and the acid carboxyl group is what gives amino acids their name. Additi­onally, 19 out of the 20 amino acids employed in protein synthesis have their side chains attached to the alpha carbon. Only glycine has no side chains among the amino acids.
Animation: protein functions
The body uses protein for a variety of purposes. It promotes metabolic reactions, supports tissue growth and repair, and synchr­onizes biological processes.
The 20 amino acids of protein
Histidine, isoleu­cine, leucine, lysine, methio­nine, phenyl­ala­nine, threonine, trypto­phan, and valine are the necessary amino acids. Alanine, aspara­gine, aspartic acid, glutamic acid, and serine are the non-es­sential amino acids.

Exocytosis
a procedure wherein the vacuole membrane and cell membrane combine to discharge the contents of a cell's vacuole to the outside.
Endocy­tosis
the process by which a live cell takes in material by allowing a vacuole to develop inside its membrane.
The plasma membrane plays a key role in most cell signaling
The condition of the plasma membrane modulates the bidire­ctional transm­ission of signals, and the context of the cell's past influences how it responds to signals.
Local and long-d­istance signaling
Long-d­istance endocrine signaling involves the production of signals by specia­lized cells and the release of those signals into the bloods­tream, where they are transp­orted to target cells in far-flung regions of the body. Hormones are signals that are created in one area of the body and move through the bloods­tream to distant locations.
The three stages of cell signaling
Reception: An outside signaling molecule is picked up by a cell. A signal is recognized when a ligand, a chemical signal, interacts to a receptor protein either within or on the surface of a cell.
2. Transd­uction: The receptor protein is altered in some way when the signaling molecule attaches to it. The transd­uction process is started by this modifi­cation. Usually, there are numerous phases in the process of signal transd­uction. The following molecule in the signal transd­uction cascade is altered by each relay molecule.
Response: The signal finally causes a particular biological reaction.
Intrac­ellular receptors
Proteins known as intrac­ellular receptors can be located inside cells, usually in the cytoplasm or nucleus.
Transd­uction by cascades of molecular intera­ctions
Signal transd­uction is the method through which cells interact with their surrou­ndings and react to them. Signaling cascades, which act as intrac­ellular transm­itters and have the ability to transport bioche­mical inform­ation between the cell membrane and the nucleus, are in charge of contro­lling this mechanism.
Protein phosph­ory­lation and dephos­pho­ryl­ation
In addition to activating or inhibiting signaling through confor­mat­ional changes, protein phosph­ory­lation and dephos­pho­ryl­ation can create binding sites for proteins with particular domains and govern cellular locali­sation.
Small molecules and Ions as second messengers
Second messengers are small molecules and ions that relay signals received by cell-s­urface receptors to effector proteins.
Regulation of transc­ription or cytopl­asmic activities
A crucial biological mechanism known as transc­rip­tional regulation enables a cell or an organism to respond to a variety of intra- and extrac­ellular inputs, to determine a cell's identity throughout develo­pment, to maintain it over the course of its existence, and to coordinate cellular activity.
The majority of cellular functions, including several metabolic pathways, including glycol­ysis, and procedures like cell division, take place within the cytoplasm. The concen­trated inner region is known as endoplasm, and the cell cortex or ectoplasm is the name of the outside layer.

Four levels of protein structure
The primary structure of a protein
The most fundam­ental level of protein structure is called primary structure. The shape, structure, and ultimately the function of the protein are determined by the amino acid sequence.
secondary structure
Secondary structure is another way to categorize protein struct­ures. The term "­sec­ondary struct­ure­" describes the regular, local structure of the protein backbone that is stabilized by amide group hydrogen bonds that occur both within and outside of individual molecules.
Helix
a typical structural pattern found in proteins. An amide hydrogen located one amino acid away from a carbonyl oxygen located four amino acids away form hydrogen bonds to maintain the helix.
Pleated sheet
A secondary structure seen in many proteins that is made up of two or more contiguous parallel polype­ptide chains that are organized so that hydrogen bonds can form between them.
tertiary structure
For a protein to work effect­ively, it must take on a final, stable, three-­dim­ens­ional structure. The organi­zation of the secondary structures into this final, three-­dim­ens­ional shape is known as the tertiary structure of a protein. The -helices, for instance, could be arranged at a straight angle or parallel to one another.
Hydrop­hobic intera­ction
The intera­ctions between hydrop­hobes and water are referred to as hydrop­hobic intera­ctions. Nonpolar hydrop­hobic compounds, which often have a lengthy carbon chain and do not interact with water molecules, are known as hydrop­hobes.
Disulfide bridges
Disulfide bonds or S-S bonds are other names for disulfide bridges. The establ­ishment of these covalent bonds between the sulfur atoms of two cysteine amino acids stabilizes the protein's tertiary and higher order structure.
Quaternary structure
Proteins made up of two or more polype­ptide chains, whether they are the same or distinct, have quaternary structure. Because they include two or more subunits, these proteins are known as oligomers. The native protein's subunit arrang­ement is described by the quaternary structure.
Collagen
Glycine, proline, and hydrox­ypr­oline are the three amino acids that make up the majority of collagen. The triple­-helix structure of collagen is made up of these amino acids, which are organized into three strands. Connective tissue, skin, tendons, bones, and cartilage all contain the protein collagen. It supports tissues struct­urally and partic­ipates in vital body functions like tissue repair and cell-t­o-cell commun­ica­tion.
Sickle cell disease
Sickle cell disease is caused by inheriting the sickle cell gene.
Denatu­ration
method that alters a protein's molecular structure. In order to achieve denatu­ration, many of the weak connec­tions or links that give a protein its highly organized structure in its normal condition must be broken.
Protein folding in the cell
The endopl­asmic reticulum is a biological region where protein folding takes place. Because proteins must be accurately folded into precise, three-­dim­ens­ional forms in order to function correctly, this is an essential biological process. Proteins that are misfolded or are unfolded improperly contribute to the pathop­hys­iology of many diseases.
X-ray crysta­llo­graphy
The experi­mental science known as X-ray crysta­llo­graphy employs incident X-ray beams to diffract into numerous distinct directions in order to identify the atomic and molecular structure of crystals.