Anatomy Ch 3

b. It is a dynamic fluid structure that is in constant flux

c. molecular transport through the membrane

True

Mitochondria

microvilli

False

mitochondrion

cytoskeleton

True

False - Interphase consists of preparing the cell for division, including obtaining nutrients (also considered the last living stage of a cell)

a. movement of a substance down its concentration gradient

c. A lysosome combines with the vacuole and digests the enclosed solid material

phospholipids Although phospholipids have a polar head, the long fatty acid tails are nonpolar, making the membrane mostly nonpolar.

forming the entire glycocalyx The glycocalyx is composed mostly of carbohydrates.

phosphate heads of phospholipids The phosphate heads of the phospholipids are polar, so they are attracted to the polar water molecules.

d. messenger RNA

Energy Osmosis is a special type of diffusion, which is always a passive process.

Hypertonic "Hyper" means "high," so a hypertonic solution has a higher solute concentration than the solution to which it is being compared.

Isotonic to each other In order to prevent the cells from either swelling or shrinking, the body fluids should be isotonic, meaning that they are at equilibrium.

The cells will lose water and shrink The hypertonic extracellular fluid will draw water out of the hypotonic intracellular fluid, so the cells will shrink. This is called crenulation.

Molecules move through transport proteins that have been activated by ATP Primary active transporters, such as the sodium-potassium pump, are activated when ATP is hydrolyzed. This activation allows for the transport of solutes across the plasma membrane against concentration gradients.

Facilitated diffusion Facilitated diffusion is a passive transport during which molecules move down their concentration gradient through transport proteins.

Exocytosis The term exocytosis literally means "out of the cell."

Glucose is a hydrophilic molecule. Glucose and other monosaccharides are polar hydrophilic molecules that are not able to traverse the hydrophobic region of the phospholipid bilayer.

Diffusion Steroid molecules are nonpolar fat-soluble molecules, which would be expected to diffuse directly across the phospholipid bilayer. Such solutes do not require a membrane protein to facilitate transport.

In primary active transport, the transport protein gets phosphorylated; in secondary active transport, the transport protein is not phosphorylated. In primary active transport, energy comes directly from the hydrolysis of ATP and the subsequent phosphorylation of primary active transporter. In secondary active transport, the solute ( usually Na+) concentration gradient produced by primary active transport provides kinetic energy to move other solutes, such as ions and glucose, against their concentration gradient. For example, glucose can be transported against its concentration gradient through a Na+ glucose symporter as Na+ moves down its concentration gradient ( a gradient produced by the Na+K+ pump).

is the division of the nucleus.

tRNA

Forms part of the protein synthesis site in the cytoplasm; may be attached to the ER or scattered in the cytoplasm

Act as "interpreter" molecules that recognize specific amino acids and nucleotide base sequences. During translation, each new amino acid is carried to the ribosome by a tRNA molecule. Each tRNA molecule carries a particular amino acid. This amino acid is dictated by the particular anticodon that the tRNA molecule contains. For a particular mRNA codon, only one tRNA molecule contains the complementary anticodon necessary to bind. Once bound, the amino acid is transferred from the tRNa molecule to the growing polypeptide.

attaches the correct amino acid to its transfer RNA

provides the energy needed for synthesis reactions

Produced in the nucleus, this molecule specifies the exact sequence of amino acids of the protein to be made

Description: 1. cellular growth and biosynthesis of organelles and proteins for various functions 2. centrioles begin to replicate

DNA replication

Description 1. Growth and biosynthesis of products to be used in mitosis 2. Centrioles finish replicating

centrosomes

nucleoli

chromosomes

chromatin

asters

Chromosomes condense as sister chromatid pairs.

Attachment of chromatid pairs to spindle microtubules.

Chromosomes move towards oposite poles of the cell.

Cytokinesis usually beings in anaphase.

mRNA carries the code for a polypeptide's sequence of amino acids. The code for each amino acid is a 3-base sequence called a codon.

One old parent 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.

transcription and translation 1) transcription, in which DNA's information is encoded into mRNA 2) translation, in which the information carried by the mRNA is decoded and used to assemble polypeptides

Telophase

Anaphase

Late prophase

Metaphase

Early prophase

The nucleotide sequence in a tRNA anticodon is an exact copy of the DNA triplet that coded for it except that uracil is substituted for thymine.

molecular transport through the membrane