AP Biology Unit 4 "Cell Communication and the Cell Cycle" Quizlet

Cell Communication

The process through which cells can detect and respond to signals in their environment

Signal Transduction Pathway

The process by which a signal on a cell's surface is converted into a specific cellular response.

Signal Transduction Pathway

Phosphorylation

The metabolic process of introducing a phosphate group into an organic molecule.

Kinase

An enzyme that transfers phosphate ions from one molecule to another

Phosphatase

An enzyme that removes a phosphate group from a molecule

Ligand

A molecule that binds specifically to a receptor site of another molecule.

G protein-coupled receptor

A signal receptor protein in the plasma membrane that responds to the binding of a signaling molecule by activating a G protein.

Second messengers

A small, nonprotein, water-soluble molecule or ion, such as calcium ion or cyclic AMP, that relays a signal to a cell's interior in response to a signal received by a signal receptor protein.

Apoptosis

Programmed cell death

Negative feedback

A primary mechanism of homeostasis, whereby a change in a physiological variable that is being monitored triggers a response that counteracts the initial fluctuation.

Positive feedback

A physiological control mechanism in which a change in some variable triggers mechanisms that amplify the change.

Cell Cycle

The regular sequence of growth and division that cells undergo

Interphase

Cell grows, performs its normal functions, and prepares for division; consists of G1, S, and G2 phases

G1 phase

The first gap, or growth phase, of the cell cycle, consisting of the portion of interphase before DNA synthesis begins.

S phase

The synthesis phase of the cell cycle; the portion of interphase during which DNA is replicated.

G2 phase

Stage of interphase in which cell duplicates its cytosol and organelles

G1 checkpoint

Checks to see if cell size is adequate; chromosomes replication is successfully completed and checks for DNA errors

G2 checkpoint

Assesses if DNA replication has occurred, go ahead signal triggers mitosis

Checkpoint

A control point in the cell cycle where stop and go-ahead signals can regulate the cycle.

Mitosis

Part of eukaryotic cell division during which the cell nucleus divides

M checkpoint

Checks for chromosomes attached to the spindle (just before anaphase)

Prophase

Chromosomes become visable, nuclear envelop dissolves, spindle forms

Metaphase

Chromosomes line up in the middle of the cell

Anaphase

Phase of mitosis in which the chromosomes separate and move to opposite ends of the cell

Telophase

phase of mitosis in which the distinct individual chromosomes begin to spread out into a tangle of chromatin

Cytokinesis

Division of the cytoplasm during cell division

Cleavage Furrow

The area of the cell membrane that pinches in and eventually separates the dividing cell

Cell Plate

In a plant cell, midline of dividing cells. Becomes the cell wall eventually.

G0 phase

A nondividing state occupied by cells that have left the cell cycle, sometimes reversibly.

Mitosis

Plays a role in growth, tissue repair, and asexual reproduction.

Cyclin

A cellular protein that occurs in a cyclically fluctuating concentration and that plays an important role in regulating the cell cycle.

Cyclin-dependent kinase (CDKs)

Enzyme to which cyclin binds during interphase and mitosis, triggering and controlling activities during the cell cycle

Cancer

Results from a variety of mutational events that cause some body cells to grow and divide uncontrollably, damaging the parts of the body around them.

CDK

Cyclin-dependent kinases. A protein kinase that is active only when attached to a particular cyclin. Activity rises and falls depending on the concentration of the cyclin partner.

Thymine

The nucleotide that hydrogen bonds with the nucleotide adenine in DNA.

Beta cells

Pancreatic cells that secrete insulin

Insulin

A protein hormone synthesized in the pancreas that regulates blood sugar levels by facilitating the uptake of glucose into tissues

Glucose transport protein (GLUT)

A type of protein molecule that works with insulin to facilitate glucose uptake by skeletal muscle fibers

Type 2 Diabetes

Diabetes of a form that develops especially in adults and most often obese individuals and that is characterized by high blood glucose resulting from impaired insulin utilization coupled with the body's inability to compensate with increased insulin production.

Growth Factor

A protein secreted by certain body cells that stimulates other cells to divide

Hormone

Chemical messengers, mostly those manufactured by the endocrine glands, that are produced in one tissue and affect another

Mitosis

Process that ensures the transfer of a complete genome from a parent cell to two genetically identical daughter cells

Mitotic cyclin

Epidermal Growth Factor (EGF)

Receptor Protein

A protein that binds to a specific signal molecule, enabling the cell to respond to the signal molecule

Dependent Variable

The outcome factor; the variable that may change in response to manipulations of the independent variable.

Independent Variable

The experimental factor that is manipulated; the variable whose effect is being studied.

% Change

((New value - old value)/old value) X 100