Chapter 3 Cells Flashcards
Isotonic
Solution with the same osmotic pressure as body fluids
Hypertonic
One with higher osmotic pressure than body fluids
Hypotonic
One with lower osmotic pressure
Filtration
Because of hydrostatic pressure, molecules can be forces through membranes by the process of filtration. Blood pressure is a type of hydrostatic pressure
Active transport
Uses ATP to move molecules from areas of low concentration to an area of high concentration through carrier molecules in cell membranes.
ATP
Adenosine triphosphate
What fuels the process of active transport?
As much as 40% of cells energy
What particles are actively transported?
Sugars, amino acids, sodium, potassium, calcium, hydrogen ions, and nutrient molecules in the intestines.
Endocytosis
Molecules that are too large to be transported by other means are engulfed by and invagination of the cell membrane and carried into the cell surrounded by a vesicle.
Exocytosis
Reverse of endocytosis
Three forms of endocytosis
Pinocytosis, phagocytosis, receptor-mediated endocytosis
Cell cycle
The series of changes a cell undergoes from the time it is formed until it reproduces
Interphase
Period of great metabolic activity in which the sell crows and synthesizes new molecules and organelles
S phase (syntheses)
The dna of the cell is replicated in preparation for cell division
G1 (gap 1) G2 (Gap 2)
The cell grows and other structures are duplicated
Mitosis
Carefully orchestrated division of the nucleus of the cell, results in each daughter cell receiving an exact copy of the the mothers cells genetic material
4 stages
What are the 4 stages of mitosis?
Prophase Metaphase Anaphase Telophase PMAT
Prophase
(1st stage of mitosis)- results in the DNA condensing into chromosomes, centrioles migrating to the poles, microtubules of the cytoskeleton reorganizing into spindle fibers, and the disappearance of the nuclear membrane.
Metaphase
Occurs as spindle fibers attach to centromeres on the chromosomes and the chromosomes align midway between centrioles
Anaphase
Occurs as the spindle fibers contract and pull the sister chomatids toward the centrioles
Telophase
Final stage of mitosis, begins when the chromosomes have completed their migrations, the nuclear envelope reappears, and the chromosomes begin to unwind.
Cytokinesis
Begins during anaphase of mitosis and continues as a contractile ring pinches the two new cells apart.
Cell differentiation
Process by which cells develop into different types of cells with specialized functions
Apoptosis
Form of cell death that is a normal part of development.
