AP Bio - Unit 4 Vocab

Cell Communication and Cell Cycle

Signal Transduction Pathway

A series of steps linking a mechanicaSl, chemical, or electrical stimulus to a specific cellular response; synaptic type of chemical signaling; Example: neurons communicate by releasing neurotransmitters across a synapse to stimulate the target cell

Kinase Enzyme

Catalyzes the transfer of phosphate groups

Ion Channel Receptor

Stop or allow flow of ions into the cell; type of receptor

Intracellular Receptor

Found in the nucleus or cytoplasm of the cell; bond to chemical messengers that are hydrophobic or very small, like nitric oxide

Protein Kinase

Transfers phosphate groups from ATP to a protein

First Messenger

Signaling molecule; extracellular; not ligand

Second Messenger

Intracellular; either a water-soluble molecule or an ion; type of messenger

Apoptosis

Cellular agents chop up DNA and fragment the organelles and other cytoplasmic components

Reception

The target cell's detection of a signaling molecule coming from outside the cell

Transduction

Happens after the receptor protein is changed by the signaling molecule; converts the signal to a form that can bring about a specific cellular response

Response

Type of cellular activity triggered by the transduced signal

Ligand

The term for a molecule that specifically binds to another molecule, usually a larger one; another name for a signaling molecule

Tyrosine Kinase

Attaches phosphates to tyrosines; catalyzes transfer of a phosphate group from ATP to tyrosine (an amino acid) on a substrate protein

cAMP

Made from ATP by adenylyl cyclase; inactivated by phosphodiesterase; a common type of second messenger

Amplification

The strengthening of stimulus energy during transduction.

G-Linked Protein Receptor

receives message for g-linked protein signaling pathway. Consists of seven alpha helices that span the plasma membrane. Changes shape when ligand molecule binds.

Cell Division

the process of creating two new cells

Mitosis

when the nucleus itself divides into two new nuclei

Cytokinesis

when the rest of the cell divides to form two new daughter cells

Chromatin

when the DNA inside the nucleus appears as disorganized, long strands

Chromosomes

when the DNA coils tightly, shortens and thickens prior to mitosis

DNA Molecule

another name for a chromosome; contains the genes

Replication

the process of chromosomes making exact duplicates

Sister Chromatids

the two sides of the "X" formed by replicated chromosomes

Centromere

a central protein bundle that connects sister chromatids

Autosomes

all chromosomes except for the sex chromosomes

Genes

codes within DNA that specify a particular trait

Alleles

two alternate forms of each gene (such as blue eyes or browneyes)

Somatic Cells

All of the body cells

Gametes

sperm and egg cells, also referred to as sex cells

Diploid Number

the total number of chromosomes in normal body cells; two matching homologs of each kind

Cell Cycle

the entire life cycle of the parent cell

Interphase

the cell is carrying out its normal everyday cell activities as well as preparing for the Mitotic phase

G1 and G2 Phases

gap phases; G1 is mostly growth and development G2 occurs after replication of chromosomes and involves replication of additional organelles and membranes in preparation for cell division

S Phase

synthesis of new DNA; also called replication

Prophase

the first phase of mitosis characterized by a disappearance of the nuclear membrane and nucleolus

Spindle Blanket

This structure will assist in pulling apart the doubled chromosomes

Metaphase

the second phase of mitosis where all of the doubled chromosomes move to the center of the cell, called the equator

Anaphase

the third phase of mitosis where the spindle fiber shorten from the poles, pulling the doubled chromosomes apart from each other, toward the poles of the cell

Telophase

the final phase of mitosis characterized by the separated chromosomes reaching the poles of the cell. The nuclear membrane and nucleolus begins to reappear around each set of chromosomes

Cell Plate

 a structure which eventually forms a cell wall that begins to grow out from the center and merely separates the two daughter cells

Microtubule

organizing center which performs the job of the centriole in plants These terms refer specifically