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Cortisol
________ is a steroid that is derived from cholesterol.
Epinephrine
________ and thyroxine are amine hormones, each synthesized from a single amino acid.
MRNA
________ conveys genetic instructions for building proteins from the nucleus to the cytoplasm.
Cytokinesis
________ occurs by a process known as cleavage.
mitotic spindle
The ________ begins to form in the cytoplasm during prophase.
Chemical signaling
________ by hormones is the function of the endocrine system, one of the two basic systems for communication and regulation in the animal body.
phosphorylation dephosphorylation system
The ________ acts as a molecular switch in the cell, turning activates on or off, or up or down, as required.
Gametes
________ are produced by a variation of cell division called meiosis.
Adenylyl cyclase
________ can then catalyze the synthesis of many molecules of cAMP so that the normal cellular concentration can be boosted.
Mitosis
________ is broken down into five stages: prophase, pro metaphase, metaphase, anaphase, and telophase.
Pyrimidines
________ have one six membered ring of carbon and nitrogen atoms.
Purines
________ have a six membered ring fused to a five membered ring.
large proportion
Together, protein kinases probably regulate the activity of a(n) ________ of the thousands of protein in a cell.
Endocrine signaling
________: secreted molecules diffuse into blood stream and trigger responses in target cells anywhere in the body.
G1
A cell grows (________), continues to grow as it copies its chromosomes (S), grows more as it completes preparation for cell division (G2), and divides (M)
receptor protein
The hormone binds to and activates the ________ and with aldosterone attached, the active form of the ________ then enters the nucleus and turns on specific genes that control water and sodium flow in kidney cells.
Communication
________ between animal cells via secreted signals is often classified by the type of secreting cell and the route taken by the signal in reaching its target.
shape change
The ________ alters the function of the protein, most often activating it.
genetic material
In both prokaryotes and eukaryotes, a crucial function of most cell divisions is the distribution of identical ________ (DNA) to two daughter cells.
Aldosterone
________ is a hormone that is secreted by cells of the adrenal gland.
binary fission
During ________ in bacteria, the chromosome replicates and the daughter chromosomes actively move apart.
Calcium
________ is more widely used than cAMP as a second messenger.
plasma membrane
Binding epinephrine to the GPCR in the ________ results in a rise in the cytosolic concentration of cAMP, a small molecule produced from ATP.
Quorum
________ sensing allows bacterial populations to coordinate the behavior of all cells in a population in activities that require a given density of cells acting at the same time (ex; biofilm, an aggregation of bacterial cells attached to a surface by molecules secreted by the cells, but only after the cells have reached a certain density)
Pheromones
________ are chemicals that are released into the external environment.
environmental stimuli
It also mediates responses to ________, regulates growth and development, and triggers physical and behavioral changes underlying sexual maturity and reproduction.
Prostaglandins
________ are a group of local regulators that are produced throughout the body and have diverse functions (ex; in the immune system they promote inflammation and the sensation of pain)
Genes
________ consist of DNA, which belongs to the class of compounds called nucleic acids- (polymers made up of nucleotides)
multicellular eukaryotes
For ________, cell division enables each of these new organisms to develop from a single cell- the fertilized egg.
DNA
________ provides directions for its own replication and also directs RNA synthesis (and control protein synthesis through RNA- (gene expression))
enzyme
A(n) ________ that transfers phosphate groups from ATP to a protein is generally known as a protein kinase.
appropriate response
For a cell to carry out the ________, cellular proteins often must integrate multiple signals.
Nucleic acids
________ are macromolecules that exist as polymers called polynucleotides.
Apoptosis
________ protects neighboring cells from damage that they would otherwise suffer if a dying cell merely leaked out all its contents, including its many digestive enzymes.
cellular response
4 ________: cell signaling leads to regulation of transcription or cytoplasmic activities.
Exocrine glands
________ have ducts that carry secreted substances onto body surfaces or into body cavities.
Certain unicellular eukaryotes
________ exhibit mechanisms of cell division that may be similar to those ancestors of existing eukaryotes.
Local regulators
________ are molecules that act over short distances, reach their target cells solely by diffusion, and act on their target cells within seconds.
hormone
A(n) ________ is a secreted molecule that circulates throughout the body and stimulates specific cells.
signal reception
2 ________: a signaling molecule binds to a receptor, causing it to change shape.
Neuroendocrine signaling
________: neurohormones diffuse into the bloodstream and trigger responses in target cells anywhere in the body.
Second messengers
________ participate in pathways that are initiated by both G protein coupled receptors and receptor tyrosine kinases (RTKs)
Paracrine signaling
________: secreted molecules diffuse locally and trigger a response in neighboring cells.
efficiency of signal transduction
They increase the ________.
large relay
Scaffolding proteins are ________ proteins to which several other relay proteins are simultaneously attached.
Autocrine signaling
________: secreted molecules diffuse locally and trigger a response in the cells that secrete them.
nervous system
They play roles in many physiological processes including blood pressure regulation, ________ function, and reproduction.
Cells
________ that are infected, damage, or have reached the end of their functional life span often undergo programmed ________ death.
Synaptic signaling
________: neurotransmitters diffuse across synapses and trigger responses in target issues (neurons, muscles, or glands)
pathway
In one ________, the gas nitric oxide is released by a cell and enters a neighboring muscle cell where it causes production of a molecule cGMP which acts as a second messenger that causes relaxation of muscles.
Endocrine signaling
secreted molecules diffuse into blood stream and trigger responses in target cells anywhere in the body
Paracrine signaling
secreted molecules diffuse locally and trigger a response in neighboring cells
Autocrine signaling
secreted molecules diffuse locally and trigger a response in the cells that secrete them
Synaptic signaling
neurotransmitters diffuse across synapses and trigger responses in target issues (neurons, muscles, or glands)
Neuroendocrine signaling
neurohormones diffuse into the bloodstream and trigger responses in target cells anywhere in the body
Hormones fall into three major chemical classes
polypeptides, steriods, and amines
Cell junctions
both animal and plants have cell junctions that allow molecules, including signaling molecules, to pass readily between adjacent cells without crossing plasma membranes
Cell surface molecule
in many animal cells, cell surface molecules on adjacent cells interact with each other, resulting in a signal passing between the cells
Signal reception
reception is the target cells detection of a signaling molecule coming from outside the cell
Signal transduction
the binding of the signal molecule changes the receptor protein in some way, initiation the process of transduction
Cellular response
the transduce signal finally triggers a specific cellular response
11.2 signal reception
a signaling molecule binds to a receptor, causing it to change shape
11.3 signal transduction
cascades of molecular interactions transmit signals from receptors to relay molecules in the cell
11.4 cellular response
cell signaling leads to regulation of transcription or cytoplasmic activities
Mitosis and the cell cycle
5.5, 12.1, 12.2 5.5 nucleic acids store, transmit, and help express hereditary information
Genes consist of DNA, which belongs to the class of compounds called nucleic acids (
polymers made up of nucleotides)
DNA provides directions for its own replication and also directs RNA synthesis (and control protein synthesis through RNA (
gene expression))
For multicellular eukaryotes, cell division enables each of these new organisms to develop from a single cell
the fertilized egg
The mitotic phase (
M phase, which includes both mitosis and cytokinesis, and is usually the shortest part of the cell cycle) alternates with a much longer stage called interphase which accounts for about 90% of the cyle
Interphase can be divided into three phases
the G1 phase (first gap), the S phase (synthesis), and the G2 phase (second gap)
Mitosis is broken down into five stages
prophase, pro metaphase, metaphase, anaphase, and telophase
In animal cells, the assembly of spindle microtubules starts at the centrosome (
sub cellular region containing material that functions throughout the cell cycle to organize the cells microtubules)
Each of the two sister chromatids of a duplicated chromosome has a kinetochore (
a structure made up of proteins that have assembled on specific sections of DNA at each centromere)
The first sign of cleavage is the appearance of a cleavage furrow (
a shallow groove in the cell surface near the old metaphase plate)
