Studied by 4 peoplepancrine signaling
cells that communicate to each other through nuerons at a closer distance
Endocrine signaling
uses hormones to talk to other cells across far distances
stages of cell signaling
Reception
Transduction
Response
Types of cell signaling
chemical, electromagnetic, mechanical
Ligand
A molecule that binds specifically to another molecule, usually a larger one AKA the receptor
what type of type of ligand will pass through the cell membrane
small nonpolar
G proein linked system
ligand attaches to a protein which adds a phosphate group that activates 1 enzyme
g protien analogy
1 ligand = 1 enzyme reaction
tyrosine kinase system
is a 2 part system, when a ligand finds each of them they can activate multiple things to happen after releasing 1 hormone
tyrosine kinase example
insulin and puberty
ion channel
protein pre that opens or cloese in response to a chemical signal
ion channel is similar to...
...sodium potassium pump
intracellular receptor is found here
cytoplasm not the membrane becuase their recptor floats
transcription factor
acticate the cytoplasmic receptor proteins
Kinase
An enzyme that transfers phosphate ions from one molecule to another
Phospatase
a protein that undoes phosphorylation by removing a phosphate group
secondary messengers
many signaling pathways that involve small, nonprotein, water-soluble ions,
cyclic AMP
acts like ATP and is the middle man/step 2 in signal transduction (form of energy that relays messages from the reveptor to somewhere else)
apoptosis pathway examples
viruses, mutations, fetal cell development
Homeostasis
a balanced state of the cell (happy place)
homeostatic control system
receptor, control center, effector
example of positive feedback
pregnancy, it ends and does not cycle
exmaple of negative feedback
homeostasis cycle, contiuous
cell division
essential to the development of a multicellular organism that begins as a fertilized egg or zygote
prokaryotic genome
single circular chromosome
Eukaryotic genome
consists of several DNA molecules that are long and linear
genome
a cells genetic information, packaged as DNA
somatic cells
(nonreproductive cells) have two sets of chromosomes
Gametes
reproductive cells (diploid)
chromatin def
The complex of DNA and proteins that condenses during cell division
chromatin formation
large rope of histones with DNA wrapped around them
plasmids
bonus DNA
46 chromosomes
body cells
sister chromatids
Identical copies of a Chromosome
centromere
Area where the chromatids of a chromosome are attached
Mitosis
division of the nucleus
Meiosis
Cell division that produces reproductive cells in sexually reproducing organisms
Cytokinesis
division of the cytoplasm
G0 phase
A nondividing state occupied by cells that have left the cell cycle, sometimes reversibly.
G1 checkpoint
checks for cell size, nutrients, growth factors and DNA damage
G1 phase
The first gap, or growth phase, of the cell cycle, cells make organells, make more cytoplasm, cell does its thing
S phase
DNA replication
G2 phase
The second growth phase of the cell cycle, cells make proteins and organelles needed for mitosis and cytikinesis
Prophase
cells chromatin tightens into desly packed chromosomes
Prophase picture
metaphase
sister chromatids are pulled along the spindle appartatus toward the cent of the cell and they line up in the middle.
Metaphase (picture)
Anaphase
the microtubules of the spindle apparatus begin to shorten, the sister chormatids separate, the chomosomes move toward the poles of the cell
Anaphase (picture)
telophase
the chromosomes arrive at the piles and begin to relax ( DNA into chromatin form), nucleous reform at each end of the cell, spindle apparatus disassembles
Telophase (picture)
Cytokinesis in animal cells
micorfilaments constrict, or pinch the cytoplasm
Cytokinesis in plants
a new structure is called a cell plate forms
density-dependant inhibition
Growth factors that appear to be a key in cell division, normal cells do this when they bump into neighboring cells , cancer does this
anchorage dependence
most animal cells also exhibit thsi for cell division, dependent on being anchored
cancer
cells that divide to much and get in the way, takes about 8x of cell death to get a mutation, happens in the S phase
tumor
a mass of cells that have grown too much
benign tumor
An abnormal mass of cells that remains at its original site in the body, relies on anchorage
malignant
lost anchorage dependents and reanchores in a new place and affects surrounding areas
metastasis
the cells unanchore themselves, reanchore, and spread throughout the body
tumor suppresor genes
a normal gene that resuls in a preoten that stops cell division, brake pedal
p53 gene
type of tumor supressed gene that is the main starter for most cancers due to mutation.
roles of P53
repairs DNA, stops cell division, does apoptosis, and gaurdian angel genome
Proto-oncogene
a normal gene that results in aprotein that starts cell division, healthy gene, responsible for normal growth
oncongenes
cancer causing genes, they are mutated cells
apoptosis
programmed cell death
telomerase
An enzyme that catalyzes the lengthening of telomeres in eukaryotic germ cells.
what genes cause cancer?
oncongenes, proto-oncongene, telomerase, anchorage dependence, density dependent inhibition, apoptosis
Genes
DNA segments that serve as the key functional units in hereditary transmission.
genetics
the scientific study of heredity and vatiation
Gametes
genes that are passed to the nxt generation through reproductive cells
Locus
specific location of the gene
karyotype
micrograph in whcih the pairs of homologous chromosomes are arranged in decreasing size
autosomes
the non-sex paired chromosomes
homologous chromosomes
pairs that carry genes that control the same inherited characters
zygote
the fertilized egg now has 2 haploid sets of chormosomes bearing genes from the maternal and paternal family lines
syngamy
these cells fuse resulting fertilization
Meiosis
Cell division that produces reproductive cells in sexually reproducing organisms creating 4 simalar chromosomes
mitosis
produces 2 identical daughter cells
chiasmata
the chromatieds are crossed and segments of the chromosmes are traded
synapsis
special proteins attach homologous tighly together
mutautions
original source of genetic diversity
3 sources of gentic variability
independent assortment
crossing over
randomfertilization
independent assortment
random orientation of tetrads at the metaphase plate
crossing over
produces recombinant chromosomes which combine genes inherited from each parent
random fertilization
any sperm can fertilize any egg
Law of Segregation
Mendel's law that states that the pairs of homologous chromosomes separate in meiosis so that only one chromosome from each pair is present in each gamete
law of independent assortment
Each pair of alleles segregates independently of each other pair of alleles during gamete formation
alleles
alternative versions of henes that account for variations in inherited characteristics
Metabolism
All of the chemical reactions that occur within an organism
metabolic pathway
A series of chemical reactions that either builds a complex molecule or breaks down a complex molecule into simpler compounds.
catabolic process
release of energy by breaking down complex molecules to simpler compounds
Anabolic process
consume energy to build complicated molecules from simpler compounds
Kinetic energy
energy of motion
potential energy
the energy that matter possess because of its location or structure
Thermodynamics 1st law
energy can be trasferred and transformed, but it cannot be created or destroyed
Thermodynamics 2nd law
every energy transformation must make the universe more disordered
Entropy
a quantity used as a measure of disorder or randomness
how do cells make macromolecules without violating the laws of thermodynamics
organisms are open systems and take in organized energy like light and replace tghem with less oredered forms, especially heat
Free energy
the portions of a systems energy that is able to perform work
Note
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