Chapter 3 - The Cellular Level Of Organization Flashcards
Active Transport
Form of transport across the cell membrane that requires input of cellular energy
Amphipathic
Describes a molecule that exhibits a difference in polarity between its two ends, resulting in a difference in water solubility
Anaphase
Third stage of mitosis (and meiosis), during which sister chromatids separate into two new nuclear regions of a dividing cell
Anticodon
Consecutive sequence of three nucleotides on a tRNA molecule that is complementary to a specific codon in an mRNA molecule
Autolysis
Breakdown of cells by their own enzymatic action
Autophagy
Lysosomal breakdown of a cell’s own components
Cell cycle
Life cycle of a single cell, from its birth until its division into two new daughter cells
Cell membrane
Membrane surrounding all animal cells, composed of a lipid bilateral interspersed with various molecules; also known as plasma membrane
Centriole
Small, self-replicating organelle that provides the origin for microtubule growth and moves DNA during cell division
Centromere
Region of attachment for two sister chromatids
Centrosome
Cellular structure that organizes microtubules during cell division
Channel protein
Membrane-spanning protein that has an inner pore which allows the passage of one or more substances
Checkpoint
Progress point in the cell cycle during which certain conditions must be met in order for the cell to proceed to a subsequence phase
Chromatin
Substance consisting of DNA and associated proteins
Chromosome
Condensed version of chromatin
Cilia
Small appendage on certain cells formed by microtubules and modified for movement of materials across the cellular surface
Cleavage furrow
Contractile ring that forms around a cell during cytokinesis that pinches the cell into two halves
Codon
Consecutive sequence of three nucleotides on an mRNA molecule that corresponds to a specific amino acid
Concentration gradient
Difference in the concentration of a substance between two regions
Cyclin
One of a group of proteins that function in the progression of the cell cycle
Cyclin-dependent kinase (CDK)
One of a group of enzymes associated with cyclone that help perform their functions
Cytokinesis
Final stage in cell division, where the cytoplasm divides to form two separate daughter cells
Cytoplasm
Internal material between the cell membrane and nucleus of a cell, mainly consisting of a water-based fluid called Custodio, within which are all the other organelles and cellular solute and suspended materials
Cytoskeleton
“Skeleton” of a cell; formed by rod-like proteins that support the cell’s shape and provide, among other functions, locomotive abilities
Cytoplasm
Clear, semi-fluid medium of the cytoplasm, made up mostly of water
Diffusion
Movement of a substance from an area of higher concentration to one of lower concentration
Diploid
Condition marked by the prescience of a double complement of genetic material (two sets of chromosomes, one set inherited from each of two parents)
DNA polymerase polymerase
Enzyme that functions in adding new nucleotides to a growing strand of DNA during DNA replication
DNA replication
Process of duplicating a molecule of DNA
Electrical gradient
Difference in the electrical charge (potential) between two regions
Endocytosis
Import of material into the cell by formation of a membrane-bound vesicles
Econ
One of the coding regions of an mRNA molecule that remain after splicing