A&P CH. 2 & CH. 3

alkaline solution A pH between 0.0 and 7.0 is acidic. A pH between 7.0 and 14.0 is basic. Therefore, a solution with a pH of 8.3 is an alkaline (or basic) solution. NaOH is an example of a basic compound.

True Salts are ionic compounds that contain a cation other than H+ and an anion other than OH-.

is based on the concentration of hydrogen ions in a solution The pH scale, which ranges from 0 to 14, is a logarithmic scale based on the concentration of hydrogen ions in a solution.

True

True

The polarity of water easily breaks the charges between the oppositely charged ions in the compound.

CH4

True

glycogen

True

True

phospholipid Phospholipids consist of a glycerol backbone linked to two fatty acid chains and a phosphorus-containing group.

lipids Triglycerides and phospholipids are two of the three major types of lipids.

a. nucleotide; nucleic acid b. eicosanoid; triglycerideamino c. acid; protein d. monosaccharide; carbohydrate b. eicosanoid; triglycerideamino

a. two back-to-back phospholipid layers with the non-polar tails facing out on both sides. b. a single layer of phospholipids with the polar heads facing outside the cell. c. two back-to-back phospholipid layers with the polar heads facing out on both sides d. a single layer of phospholipids with the polar heads facing inside the cell c. two back-to-back phospholipid layers with the polar heads facing out on both sides

a. "If you remove all fat from your diet, you may be able to lower your cholesterol even further." b. "Make sure that you read food labels carefully. Even frozen vegetables can be loaded with cholesterol." c. "Be glad that your levels are normal. Most of our patients have levels that are much too high." d. "A normal cholesterol level is a good thing. Your cells depend on cholesterol to stay healthy, and you can't make vital hormones without it." d. "A normal cholesterol level is a good thing. Your cells depend on cholesterol to stay healthy, and you can't make vital hormones without it."

False

a. They may be denatured or coagulated by heat or acidity. b. They appear to be the molecular carriers of coded hereditary information. c. They have both functional and structural roles in the body. d. Their function depends on their three-dimensional shape. b. They appear to be the molecular carriers of coded hereditary information.

True DNA provides the basic instructions for building every protein in the body. RNA carries out the orders for protein synthesis issued by DNA.

sequence of the nucleotides

a. DNA is a long, double-stranded molecule made up of A, T, G, and C bases. b. Three forms exist: DNA, RNA, and tDNA. c. tDNA is considered a "molecular slave" of DNA during protein synthesis. d. RNA is a long, single-stranded molecule made up of the bases A, T, G, and C. a. DNA is a long, double-stranded molecule made up of A, T, G, and C bases.

ATP When broken (hydrolyzed), the high-energy phosphate bonds in the ATP molecule release the energy used to do cellular work.

True ATP is the primary energy-transferring molecule in cells, and it provides a form of energy that is immediately usable by all body cells. Chemically, the triphosphate tail of ATP can be compared to a tightly coiled spring ready to uncoil with tremendous energy when the catch is released. Actually, ATP is a very unstable high-energy molecule because its three negatively charged phosphate groups are closely packed and repel each other.

cytoplasm, plasma membrane, and nucleus Human cells have three main parts: the plasma membrane, the cytoplasm, and the nucleus.

True

A. Panel A shows both passive and active transport processes of solutes mediated by integral membrane proteins.

the binding of a chemical messenger activating a cytoplasmic enzyme, such as kinase, that leads to specific cellular responses. Once activated by the binding of a specific chemical messenger, such as a hormone, the receptor protein initiates cellular responses by activating specific signal transduction pathways.

D. Panel D shows recognition of one cell by another via the glycocalyx.

gap junction A gap junction is a communicating junction between adjacent cells.

phospholipids The plasma (cell) membrane is a phospholipid bilayer, composed of two parallel sheets of phospholipid molecules lying tail to tail, with their polar heads exposed to water on either side of the membrane. This allows the plasma membrane to separate the intracellular fluid (the ICF) from the extracellular fluid (ECF).

a phospholipid bilayer surrounding the cell

diffusion down a concentration gradient Transport by diffusion of a molecule down its concentration gradient is a spontaneous process that requires no energy input.

swell and burst

The cells will swell and ultimately burst.

a hypertonic solution

Active transport is ATP dependent, whereas passive transport uses only the kinetic energy of the particles for movement across the plasma membrane. In active transport, the cell provides the metabolic energy (ATP) needed to move substances across the plasma membrane (against their concentration gradient). In passive transport, substances cross the plasma membrane (down their concentration gradient) using kinetic energy, without any energy input from the cell.

False Channel-mediated diffusion is a form of passive, not active, transport. Any type of diffusion results from substances moving down their concentration gradient, a form of kinetic energy. In order to actively move, or pump, substances against their concentration gradient, chemical energy must be used. ATP directly, or indirectly, provides the chemical energy for active transport.

a. Endocytosis and exocytosis are passive transport mechanisms. b. Unlike endocytosis, exocytosis does not rely on protein interactions with the plasma membranes. c. During exocytosis, substances from inside the cell are moved outside. d. Exocytosis involves infolding of the plasma membrane. c. During exocytosis, substances from inside the cell are moved outside. Vesicular transport processes that eject substances from the cell interior into the extracellular fluid are called exocytosis. Exocytosis is a form of active transport; thus, it requires energy, usually in the form of ATP.

movement of a substance down its concentration gradient

a. phagocytosis b. pinocytosis c. osmosis d. exocytosis c. osmosis

phagocytosis

pinocytosis

False

synthesis of proteins Structure A is the rough endoplasmic reticulum (ER). The figure illustrates how proteins are synthesized on ribosomes bound to the rough ER before being modified and secreted or packaged.

modification and packaging of proteins This function is handled by the Golgi apparatus within the endomembrane system; it functions in the sorting and modifying of membrane-bound proteins being transported to various cellular locations.

exocytosis of secretory proteins The event indicated by C includes the fusion of a secretory vesicle with the plasma membrane and the subsequent release of the vesicle contents to the extracellular space.

a. mitochondrion: packaging proteins and lipids b. Golgi apparatus: produce energy for the cell c. smooth endoplasmic reticulum: metabolism of lipids d. lysosome: protein synthesis c. smooth endoplasmic reticulum: metabolism of lipids The smooth ER also plays a role in synthesizing steroid hormones, absorbing and transporting fats, detoxifying toxins, and breaking down glycogen.

synthesis of cellular membrane components The rough ER synthesizes all proteins secreted from the cell; it also functions as the cell's "membrane factory" because integral proteins and phospholipids that form part of all cellular membranes are manufactured there.

ribosomes Proteins are synthesized at ribosomes. Free ribosomes float freely in the cytoplasm and produce soluble proteins that function in the cytosol, as well as those imported into mitochondria and some other organelles. Fixed ribosomes, which stud the rough endoplasmic reticulum, synthesize proteins destined either for incorporation into the cell membrane or lysosomes, or for export from the cell.

True Born as endosomes that contain inactive enzymes, lysosomes are spherical, membranous organelles containing activated digestive enzymes. Lysosomes are large and abundant within phagocytes, the cells that dispose of invading bacteria and cell debris. Lysosomal enzymes can digest almost all kinds of biological molecules. They work best in acidic conditions and so are called acid hydrolases.

Golgi apparatus

mitochondria

is the site of ribosome assembly in a cell Nucleoli ("little nuclei") are the dark-staining spherical bodies found within the nucleus where ribosomal subunits are assembled. They are not membrane bounded. Typically, there are one or two nucleoli per nucleus, but there may be more. Nucleoli are usually large in growing cells that are making large amounts of tissue proteins.

one old template strand and one new daughter strand This mechanism is called semiconservative replication and is based on the ability of each strand of the DNA double helix to function as a template for the synthesis of the opposite strand.

Its DNA must be replicated exactly so that identical copies of the cell's genes can be passed on to each of its offspring. Before a body cell begins mitosis, it must replicate its DNA so that each daughter cell will have the same DNA as the parent cell.

is division of the genetic material within the nucleus

metaphase

True

True

B. Molecule B is a complement of the DNA template (A) and contains ribonucleotides, as indicated by the presence of uracil (U). This is consistent with molecule B being an mRNA molecule.

transcription Transcription is the synthesis of RNA using DNA as a template.

ribosome The codons within the mRNA (B) are recognized by corresponding tRNA molecules within cytoplasmic ribosomes during protein translation.

t-RNA Transfer RNA (tRNA) are small, roughly L-shaped molecules that ferry amino acids to the ribosomes. There they decode mRNA's message for the amino acid sequence of the polypeptide to be built, a process called translation.

tRNA

a segment of DNA that carries the instructions for one polypeptide chain

False