Unit 4- Cell Communication and Cell Cycle Flashcards
Binary fission
prokaryotic cell division; double the DNA, double the size, then split apart
List steps of the cell cycle
G1 –> S –> G2 –> M
growth 1, synthesis, growth 2, mitosis, etc.
Interphase consists of
G1, S, G2, 90% of the cell cycle
The physical separation of newly formed daughter cells of cell division is also known as
cytokinesis
List the steps of mitosis in order
-prophase
-metaphase
-anaphase
-telophase
What stage of mitosis when the nucleolus disappears and mitotic spindle forms?
prophase
Sister chromatids line up at the middle during…
(mitosis)
metaphase
Sister chromatids are split apart at…
(mitosis)
anaphase
Nuclei of new cells re-form; chromatin uncoils at…
(mitosis)
telophase
Each chromosome pairs with its homolog; there is crossover
(meiosis)
Prophase I
Chromosome pairs align along the middle of the cell, ready to split apart (meiosis)
Metaphase I
Homologous chromosomes split apart (meiosis)
Anaphase I
Nuclear membrane reforms; daughter cells are now haploid(n)
(meiosis)
Telophase I
Nucleus disappears, spindle apparatus forms (meiosis)
Prophase II
Sister chromatids line up at middle
Metaphase II
Sister chromatids are split apart
Anaphase II
Nuclei of new cells reform; chromatin uncoils
Telophase II
A haploid cell contains _____ copy of each cell
1
A ________ cell contains 2 copies of each chromosome
diploid
Chromosomes that are similar in shape, size, and function are called ______________
homologous
The process of male gamete formation is called ____________. (4 sperm in one cell)
spermatogenesis
The process of female gamete formation(one ovum from each cell)
oogenesis
Checkpoints occur in the cell cycle to promote ____________.
growth
Cells stop growing when certain density is reached (runs out of food) during _________-_____________ inhibition.
density- dependent
Cyclins and protein kinases
cyclin combines with CDK to form a structure known as MPF that pushes cell into mitosis when enough is present
Cells uses energy to maintain homeostasis through _____________ _____________, _____________ ____________, and for __________.
feedback mechanisms, communcation w/ cells, replication
During signal transduction, _______ is responsible for amplyfing intracellular signals
cAMP
In a signal transduction pathway, first, the ________ binds to the receptor then sets of a cascade of events
ligand
When the ligand binds to the receptor in a signal transduction pathway, the shape of the receptor __________ ( stays the same/changes), resulting in an ____________( activation/ deactivation) of an enzyme.
changes, activates
What type of signaling involves the direct contact between cells during communication?
Direct cell to cell signaling
What type of signaling involves cells that are close to one another but NOT in direct contact. Signals can diffuse only over SHORT distances.
Paracrine signaling
Where is the receptor located for hydrophilic ligands?
on the cell membrane
Where is the receptor located for hydrophobic ligands that are small enough to cross the membrane?
INSIDE the cell
Signaling that involves…
- cells far apart
-hormone is released into the extracellular fluid
- steriod hormones are lipid soluble molecules that pass through membrane, attach to intracellular receptor
(think blood vessel)
endocrine signaling
Signaling that involves…
- nerve cell, neuron, target cell
- chemical synapse
- release of neurotransmitters from the neuron into the synaptic gap to target the target cell
synaptic signaling
Signaling that involves…
- a cell sends a signal to itself
-plays important role in cell development and immune system
autocrine signaling
The addition of phosphate groups is known as…
phosphorylation
Phosphorylation is catalyzed by enzymes called ____________.
kinases
The dephosphorylation of proteins( removal of phosphate groups) is cataylzed by the enzyme ___________.
phosphatases
What is the overall goal of phosphorylation?
activation or inactivation proteins in the signal transduction pathway
Why would calcium( Ca) be useful in signal transduction pathways?
it serves as a secondary messenger, when it binds to the protein, the shape changes, leading to a change in function
Cyclic AMP( cAMP) is involved in many signal ________ pathways
cascade
Protein hormones activate __________ through a multi-step process that begins with protein- hormone activation of relay proteins such as ______________.
cAMP, G- proteins
What is the main purpose of G- proteins?
directly activate adenyl cyclase, which produces cAMP
The cell prepares itself for synthesis, making sure that is has all of the raw materials for DNA synthesis, during what stage of the cell cycle?
G1
DNA is copied so that each daughter cell has a complete set of chromosomes during what stage of the cell cycle?
S
The cell prepare itself for mitosis(body cells) and/or meiosis(gametes) during the _____ phase.
G2
The last phase is the ___ where the cell seperates into 2 new cells
M (mitosis)
What phases make up interphase?
A cell spends about ____ % of its lifetime here
G1, S, G2
90%
Mitosis consits of how many phases? What is followed by imediately after?
4
prophase, metaphase, anaphase, telophase
cytokinesis
Cytokinesis is the ___________ __________ ____ ______________ ______.
physical separation of daughter cells.
What protein controls other proteins through the addition of phosphate groups?
protein kinase
What protein is accumulated during interphase?
Cyclin
Apoptosis
cells undergo programmed cell death
- maintains proper balance of cells in human body, gets rid of cancer cells
Negative feedback
occurs when a hormone acts to directly or indirectly inhibit further secretion of the hormone of interest.
- body temp when hot -> sweats
Positive feedback
women delivering baby
- keeps stimulus in the same direction, speeds up action
What phase of the cell cycle does crossover occur?
A. Metaphase of mitosis
B. Metaphase I of mitosis
C. Prophase I of meiosis
D. Prophase of meiosis
C. Prophase I of meiosis
- humans only, production of offspring
