cells and membrane vocab

prokaryotic cell

organelles that aren’t bound by a membrane and don’t have a nucleus

ex: bacteria cells

eukaryotic cell

membrane-bound organelles that have a nucleus

ex: plant and animal cells

nucleus

function: it protects the DNA

structure: a nuclear envelope, double membrane that is fused in spots to create pores

nucleolus

function: ribosome production, it’s found inside the nucleus it builds ribosome subunits from RNA and proteins

cytoplasm

the contents of the cell bounded by the plasma membrane; in eukaryotes, its the portion exclusive of the nucleus, all cells have this (it’s water)

cytosol

the semi-fluid portion of the cytoplasm

nucleoid region

a non-membrane-enclosed region in a prokaryotic cell where it’s chromosome is located

plasma membrane

the membrane at the boundary of every cell that acts as a selective barrier, regulating the cell’s chemical composition

ribosome

function: protein production

structure: rRNA and protein, not membrane bound

free ribosome

in the cytoplasm, suspended in the cytosol, it makes proteins just for that cell

bound ribosome

attached to the endoplasmic reticulum, makes proteins for exocytosis (proteins for export)

endomembrane system

it happens inside the layer of phospholipids, it uses proteins for export, and involved organelles

1. nucleus (DNA → RNA)

2. ribosomes (RNA → protein)

3. endoplasmic reticulum (highway system)

4. golgi apparatus (processes proteins)

5. vesicles (helps export proteins)

smooth endoplasmic reticulum (ER)

function: manufactures membranes, synthesis of lipids and carbs, synthesis and hydrolysis of many compounds

structure: membrane connected to nuclear envelope and extends throughout the cell

rough endoplasmic reticulum

function: manufactures membranes, makes and processed exportable proteins

structure: membrane connected to nuclear envelope and extends throughout the cell, it has ribosomes attached to it

golgi apparatus

function: a modifier of substances, it finishes, sorts, and tags cell products to ensure proper delivery, it “ships” the products in vesicles

structure: a stack of membranes

peroxisomes

they are able to transfer toxic H+ protons to H2O to make a less toxic H2O2 (hydrogen peroxide). It’s good for detoxification and various metabolic activities. Humans have an enzyme (found in the liver) in our bodies that is able to break up that H2O2

mitochondria

a very unique double membrane organelle that converts chemical energy (glucose) into usable energy, they are have their own ribosomes and DNA, its found in plant and animal cells

chloroplast

a very unique double membrane organelle that converts sunlight into chemical energy (glucose), it has it’s own ribosomes and DNA, it’s only found in plant cells

cytoskeleton

the structure of the cytoplasm that is made up of protein tubes/rods

microtubules

the thickest cell shape attachment for the structure of the cytoskeleton in an eukaryotic cell

microfilaments

the thinnest cell shape attachment for the structure of the cytoskeleton in an eukaryotic cell

centriole

a structure in the centrosome of an animal cell composed of a cylinder of microtubule triplets

flagella

a cytoskeleton that has been pushed out to the surface, it’s a long cellular appendage specialized for locomotion, looks like a balloon string

cilia

as cytoskeleton that has been pushed out to the surface, it’s specialized for locomotion and moving fluid past the cell, looks like arm hair

glycoprotein

a protein with one or more covalently attached carbohydrates

central vacuole

found in plant cells, it’s a large membranous sac with diverse roles in growth, storage, and sequestration of toxic substances

cell wall

a protective layer for the plasma membrane in plant cells, cellulose and chitin are important for the structure

extracullular matrix (ECM)

the meshwork surrounding animal cells, consisting of glycoproteins, polysaccharides, and proteoglycans that are synthesized and secreted by cells

plasmodesmata

cytoplasmic continuation between plant cells, an open channel that connects the cytoplasm of adjacent plant cells, used for communication

tight junctions

a type of intercullular junction between animal cells that prevents the leakage of material through the space between cells, it’s like glue, it adheres two cells together.

desmosomes

a type of intercullular junction in animal cells that function as a rivet, fastening the cells together, it acted like a staple holding the cells together

gap junctions

a type of intercullular junction in animal cells consisting of proteins surrounding a pore that allows the passage of materials between cells, cytoplasmic continuation between animal cells, it’s used for communication

selective permeability

a property of biological membranes that allows them to regulate the passage of substances across them

fluid mosaic model

the cell membrane, it consists of many parts that are always moving

integral proteins

proteins that go through the membrane, it penetrates the lipid bilayer and acts like a door, it’s used for transporting proteins

peripheral proteins

a protein on the outside of the membrane that flags for identification and has attachment spots where it’s loosely bound to the membrane site

concentration gradient

a region where the density of a substance increases or decreases, low → high (active transport), high → low (diffusion and facilitated diffusion)

quantity difference

passive transport

the movement of a substance that doesn’t require any energy (osmosis, diffusion, and facilitated diffusion)

hypertonic

a solution that has more solute and less water (above solute)

hypotonic

a solution that has less solute and more water (below solute)

isotonic

a solution that has equal solute and and equal water

osmosis

the diffusion of water across a semi permeable membrane, from a high concentration of water to a low concentration of water

turgid

a plant cell that is swollen from being placed in a hypotonic solution, the cell wall prevents the cell from bursting

flaccid

a plant cell that is limp from being placed in an isotonic solution, water is leaving the cell

active transport

the diffusion of substances against concentration gradient (low → high), it uses a protein pump to move substances and requires ATP

membrane potential

the difference in electrical charge (voltage) across a cells plasma membrane due to the differential distribution of ions

cotransport

the coupling of the “downhill” diffusion of one substance to the “uphill” transport of another against its own concentration gradient

exocytosis

the movement of biological molecules and particulate matter out of the cell via vacuoles and vesicles, it’s the last step in the endomembrane system

endocytosis

the movement of biological molecules and particulate matter into the cell via vesicles and vacuoles

phagocytosis

a type of endocytosis in which large particulate substances or small organelles are taken up by a cell, “cellular eating”

pinocytosis

a type of endocytosis in which the cell ingests extracellular fluid and it is dissolved solutes, “cellular drinking”

diffusion

the movement of substances (across a membrane) from a high to low concentration, no help or energy is needed

facilitated diffusion

the movement of a substance (across a membrane) from a high to low concentration with the help of integral protein channels