Chapter 3

reproductive cells, sex cells - the sperm and the egg (oocyte)

all other cells of the body. 

water loving, polar charged

repelled by water, non-polar

molecules that have both polar and nonpolar parts. 

extend into or through the lipid bilayer among the fatty acid tails and are firmly embedded in it. 

not as firmly embedded in the cell membrane.  attached to the polar heads of membrane lipids or to integral proteins at the inner or outer surface of the membrane. 

proteins that span the entire lipid bilayer and protrude into both the cytosol and extracellular fluid.

carbohydrate portions of glycolipids and glycoproteins form a sugary coat on the outside of cells. 

passive process in which substances move freely through the lipid bilayer of the plasma membranes of cells without the help of membrane transport proteins.  NO ENERGY IS REQUIRED, FREE FLOWING MOVEMENT THROUGHOUT MEMBRANE.  small resp. gases (co2 and o2, hydrophobic steriods, little bit of h2o and etoh.

an integral membrane protein assists a specific substance across the membrane.  

an active process because energy is required for carrier proteins to move solutes across the membrane against a concentration gradient.  

net movement of a solvent through a selectively permeable membrane.  passive process.  solvent is water, which moves by osmosis across plasma membranes from an area of higher water concentration to an area of lower water concentration.  

measure of the solutions ability to change the volume of cells by altering their water content. 

solution that has a LOWER concentration of solutes than the cytosol inside RBCs. water goes inside cells. 

has a HIGHER concentration of solutes than the cytosol inside RBCs causing cells to shrink.  

any solution in which a cell, for example, a red blood cell, maintains its normal shape and volume.  

used to move a substance into, across, and out of a cell. 

bringing something into the cell.  transports molecules or particles that are too large to move by diffusion or active transport.  

release something from the cell.  reverse of endocytosis.  membrane enclosed structures called secretory vesicles that form inside the cell fuse with the plasma membrane and release their contents into extracellular fluid. 

"cell eating"  vesicle forms around a solic through the action of pseudopods.  

"cell drinking"  process by which cells take in tiny droplets of liquid.  part of the cell membrane indents and the indentation contains some of the surrounding fluiod; a vesicle is formed and pinches off.  

• moves only substances for which the cell membrane has specific receptors. 
• substances bond to the membrane receptors. 
• binding triggers the cell membrane to indent and form a vesicle around the substance and pull it inside. 
• allows cells to respond to specific substances, such as cholesterol and hormones, when they are present in very low concentrations. 

masses of insoluble material found in the cytosol of cells.  most commonly stored nutrients - glycogen/fat in liver.  fat droplets in adipose. 

digestion of worn out organelles by lysosomes.  liver cells recycle approximately half of the cell contents every week. 

process in which a cell self destructs.  

specialized structures that have characteristic shapes and perform specific functions in cellular growth, maintenance and reproduction.  

loosely coiled threadlike strands of DNA and protein. 

chromatin is wound into a fiber which is the basis of chromosomes.  consist of 2 sister chromatids.  3 parts: p arms, q arms, and centromeres.  containes thousands of genes per each. 

the distribution of two sets of chromosomes, one set into each of two separate muclei.  

results in the production of haploid cells that contain only 23 chromosomes. 

just before cell division takes place the DNA replicates (duplicates) and the loops condense even more, forming a pari of chromatids. 

the constricted portion of a chromosome where the two chromatids are joined; serves as the point of attachement for the microtubules that pull chromatids during anaphase of cell division. 

a broad group of diseases characteried by abnormal cell reproduction.  cancer cells compete with healthy cells for nutrients and can invade healthy structures and impair their function.  

tumors that do not metastasize or spread.  

spreads due to cells that detach from tumor and enter blood or lymph.  

• cells are the structural building blocks of all plants and animals. 
• Cells are produced by the division of preexisting cells
• cells are the smallest structural unites that perform all vital functions. 

• phospholipids
• cholesterol
• glycolipids

• function as
• channels (pores)
• transporters
• receptors
• enzymes
• cell-identity markers
• linker

consists of all the cellular contents between the plasma membrane and the nucleus. made up of cytosol and organelles.