Ch. 3 Cells (Marieb)

Pinocytosis

cell drinking. A form of endocytosis

Phagocytosis

cell eating. A form of endocytosis.

Microvilli

finger-like extensions that increase surface area for increased absorption

Interstitial fluid or extracellular fluid

fluid between cells

Intracellular fluid

fluid within the cell

Active transport

for moving molecules from low to high concentration. Requires ATP.

Organelles

structures that perform specific functions in the cell

hydrophilic

water loving.....can dissolve in water. Polar.

flagella

whiplike tails found in one-celled organisms to aid in movement (only on sperm of humans)

Vesicular transport

(bulk); Transport large quantities of material through exocytosis or endocytosis; Key for immune system phagocytes

transcription

(genetics) the organic process whereby the DNA sequence in a gene is copied into mRNA

translation

(genetics) the process whereby genetic information coded in messenger RNA directs the formation of a specific protein at a ribosome in the cytoplasm

Gap junctions

Allow neighboring cells to communicate. Protein tubes called connexons are found here. Found in the heart.

Golgi apparatus

An organelle in eukaryotic cells consisting of stacks of flat membranous sacs that modify, store, and route products of the endoplasmic reticulum (proteins). Place where proteins are modified sorted and released in transport vesicles.

Isotonic

Extracellular and intracellular concentrations are the same

Tight junctions

Form a junction between cells that is impermeable

Desmosomes

Hold cells tightly together. Obvious when your skin peels off in sheets.....the cells stay anchored together.

Solvent

In a solution, the substance in which the solute dissolves. In the body this is typically water.

microfilaments

Long, thin fibers that function in the movement and support of the cell

Endocytosis

Materials enter the cell, such as with Phagocytes lysing bacteria

centrioles

One of two tiny structures located in the cytoplasm of animal cells near the nuclear envelope; play a role in cell division.

filtration

Process by which water and solutes are forced through a membrane by hydrostatic pressure.

intermediate filaments

Threadlike proteins in the cell's cytoskeleton that are roughly twice as thick as microfilaments.

Cytoplasm

a jellylike fluid inside the cell in which the organelles are suspended

Peripheral proteins

attached to the SURFACE of the bilayer, either inner or outer side.

lysosomes

cell organelle filled with digestive enzymes needed to dispose of used up cellular materials

Integral protein functions

cell recognition, pores, structural support. Usually transmembrane--go all the way through the layers.

Nucleus

control center of the cell

facilitated diffusion

diffusion using a carrier protein, uses no ATP and still requires concentration gradient; to move molecules that are too large or insoluble (too charged)

anticodon

group of three bases on a tRNA molecule that are complementary to an mRNA codon

cilia

hair-like processes from the surface of epithelial cells, such as those of the bronchi, that provide upward movement of mucus cell secretions

microtubules

hollow tubes of protein about 25 nanometers in diameter, support the cell and moves organelles within the cell

Hypertonic

if the solution is hypertonic to the cell, the cell shrinks, known as crenation (water moves OUT of cell towards the solute).

Hypotonic

if the solution is hypotonic to the cell, the cell expands (water moves INTO the cell towards the solute)

chromatin

long strands of DNA and proteins found in the nucleus; condense to form chromosomes

Exocytosis

material exits the cell through vesicular transport

diffusion

movement of substances down its concentration gradient from high to low concentration (passive)

cytoskeleton

network of protein filaments within some cells that helps the cell maintain its shape and is involved in many forms of cell movement (microfilaments, microtubules and intermediate filaments)

hydrophobic tails

nonpolar region of the plasma membrane. Water hating.

semi permeable

only select substances pass through

Plasma membrane

outermost boundary of cell that controls what goes in/out of cell. Cell barrier

Active processes

require energy to pass through the cell membranes (ATP)

Osmosis

simple diffusion of H2O; water moves TO highest particle concentration

ribosomes

small round structures that make proteins (along with mRNA and tRNA and rRNA)

simple diffusion

small substances move directly through bilayer

Cholesterol

stabilizes the phospholipid membrane, making it more fluid

smooth er

synthesis of lipids, phospholipids and steroid sex hormones-help detoxify drugs and poisons (liver cells) involves adding hydroxyl groups to drugs to make soluble and easier to flush from body

Tonicity

the ability of solution to change the shape of cell by altering intracellular water levels

solute

the dissolved substance in a solution

mRNA

the template for protein synthesis

passive transport

things can cross the membrane without needing energy. Small nonpolar (uncharged) molecules

tRNA

transfer RNA; type of RNA that carries amino acids to the ribosome. There are 20 different tRNA's, one for each amino acid.

peroxisomes

Contain oxidase enzymes that detoxify alcohol, hydrogen peroxide, and other harmful chemicals such as free radicals

Integral proteins

Inserted INTO the phospholipid bilayer (can see on both sides). Go through the entire plasma membrane.

Rough Endoplasmic Reticulum

Protein synthesis. Studded with ribosomes.

Nucleolus

Site of RNA and ribosome synthesis. In Nucleus

free radical

an atom or group of atoms with at least one unpaired electron

Mitochondria function

break C-C bonds in glucose to allow ADP to form ATP. Makes energy for the cell. The powerhouse of the cell