unit 2 bio

macromolecules and their monomers

carbohydrates- monosaccharides

lipids- fatty acids and glycerol

proteins- amino acids

nucleic acids- nucleotides

selective permeability

nonpolar molecules are hydrophobic and can cross the membrane easily

polar molecules and IONS are hydrophilic and CANNOT cross the membrane that easily, must pass through transport proteins

WATER moves through special transport proteins called aquaporins

isotonic vs hypotonic vs hypertonic

no net movement, loses water to environment (shriveled), water enters faster than it leaves (swells and bursts)

WATER moves from hypotonic to hypertonic.

passive vs facilitated diffusion

substance travels from more to less concentrated, travels through transport proteins

active vs passive transport

low to high concentration, needs ATP

high to low concentration, does not need energy

how do transport proteins transport??

through hydrophilic channels or binding loosely to molecules and carry them through the membrane

exocytosis vs endocytosis

exocytosis - moves things out of the cell by vesicles from the cell’s interior fuse with the cell membrane and expelling their contents

endocytosis - moves things in the cell by forming new vesicles from the plasma membrane (opposite of exocytosis)

vesicle vs vacuole

vacuole stores and releases macromolecules and waste, vesicle carries products in, out, and within a cell

3 stages of cell communication and signaling

reception - signal molecule comes from outside the cell and target cell detects it

transduction - turns signal into a form that can bring response

response - cellular response to the signal

ligand, receptor, and different types of receptors

ligand - signal molecule

receptor - receives and responds to signal molecule

intracellular - found in cytoplasm or nucles, ligand must be hydrophobic and cross the plasma membrane

plasma membrane receptors - binds to water-soluble ligands

cell cycle

INTERPHASE:

g1- cell growth

s phase- DNA replication

g2- grows and prepares for mitosis

m phase- mitosis!

mitosis

prophase- chromatin coils up, nucleoli disappears, spindle forms

prometaphase- microtubules attach to chromosomes, centromere holds sister chromatids by microtubules attaching to protein kinetochore

metaphase- chromosomes line up to middle of the cell, centrioles go to opposite sides of the cell

anaphase- sister chromatids separate, cell elongates

telophase and cytokinesis- nuclear envelope forms, chromatin less coilled, cytokinesis beings when cytoplasm is divided

organelles and their function

nucleus- DNA, regulates gene expression

mitochondria- ATP synthesis

golgi apparatus- modifies, packages, and sorts proteins

endoplasmic reticulum (smooth)- detoxifies drugs, lipid synthesis, metabolizes carbohydrates

endoplasmic reticulum (rough)- ribosomes, synthesizes proteins

lysosomes- digests and breaks down macromolecules

ribosomes- found bound to ER or free in the cytoplasm, mRNA messages ribosome with genetic instruction from DNA to synthesize proteins

reception, transduction, response

target cell’s detection of a signal molecule coming from outside the cell, the conversion of the signal to a form that can elicit a cellular response, the specific cellular response to the signal molecule

protein phosphatase

enzymes that remove phosphate groups and activate protein kinases

second messengers

signaling pathways involving small, non-protein water soluble molecules or ions that can initiate phosphorylation cascade

osmosis vs diffusion

osmosis - water moving from an area of low solute concentration to high solute concentration

diffusion - movement of molecules from an area of high concentration to low concentration

prokaryotes vs eukaryotes

prokaryotes have single and circular chromosomes, no nucleus, smaller, and no membrane bound organelles in the cytosol, found in bacteria and archaea

eukaryotes have multiple and linear chromosomes, nucleus, bigger, and contains membrane bound organelles in cytosol, found in eukarya

somatic cells vs gametes

somatic cells - chromosomes except sex cells (diploid)

gametes - sperm and egg cells (haploid)