AP Biology - Q3 Final

pancrine 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

1. Reception
2. Transduction
3. 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

1. independent assortment
2. crossing over
3. 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