Texes 8-12 life science

• simplest unit of structure
• combine to form polymers through condensation
• break apart through hydrolysis

• -contain a ratio of 2 hydrogen atoms for each carbon and oxygen
• -include sugars and starches
• -function in the release of energy

• simplest sugars
• include glucose, fructose, and galactose
• major nutrients for cells

• made by joining 2 monosaccharides through condensation to form a glycosidic linkage
• maltose - 2 glucoses
• lactose - glucose + galactose
• sucrose - glucose + sucrose

• consist of many monomers joined together
• storage materials hydrolized to as needed to provide sugar for cells or building materials for structures protecting the cell
• examples: starch, glycogen, cellulose, chitin

• major energy storage molecule in plants
• made up of many glucose molecules

• major energy storage molecules in animals
• made of many glucose molecules

• found in plant cell walls, function is structure
• adds fiber to diet because many animals lack the enzymes necessary to hydrolyze cellulose

• found in the exoskeleton of arthropods and fungi
• contains an amino sugar

• composed of glycerol (alcohol) and three fatty acids
• examples: fats, phospholipids, steroids

• long carbon skeletons
• solids at room temperature and come from animals
• examples: lard, butter

• vital component in cell membranes
• one or two fatty acids are replaced by phosphate group linked to a nitrogen group
• polar hydrophillic head, hydrophobic tail

• insoluble and composed of a carbon skeleton consisting of four interconnected rings
• cholesterol is the precursor from which other steroids are synthesized
• hormones are steroids and do not dissolve in the body

• function in:
• structure and support - connective tissue, hair feathers, quills
• storage of amino acids-albumin in eggs
• transport of substances- hemoglobin
• coordination body activities - insulin
• signal transduction - membrane receptor proteins
• contraction - muscles
• body defense - antibodies
• function as enzymes to speed up chemical reactions

• act as biological catalysts to speed up reactions.
• most diverse of all types of proteins
• act on a substrate ( the material to be broken down or put back together)

• the shape of the enzyme is specific because it fits into the subsrtate like a key fits into a lock.
• Aids in holding molecules close together so reactions can easily occur

• an enzyme can stretch and bed to fit the substrate
• most accepted theory

block the substrate from entering the active site of the enzyme reduce productivity

• bind to the enzyme in a location not in the active site but still interrupt substrate binding
• in most cases alter the shape of the enzyme

can exist in two shapes, they are active in one form and inactive in the other

• methanogens
• halobacteria
• thermacidophiles

• found only in photosynthetic organisms
• similar to mitochondria
• chloroplasts - site of photosynthesis
• chromoplasts - make and store yellow and orange pigments
• amyloplasts - store starch and are used as a food reserve

mitochondria and chloroplasts were once free living and possibly evolved from prokaryotic cells. At some point they were ingested into eukaryotic cells and maintained a symbiotic relationship with them. Have their own DNA, RNA, ribosomes, and are capable of reproduction

• found in both animal and plant cells
• composed of protein filaments attached to the plasma membrane and organelles
• framework for the cell and aids in cell movement
• 3 types: microtubles, intermediate filaments, microfilaments

virus enters a host cell and makes copies of its nucleic acids and protein coats and reassembles. It then lyses or breaks out of the hoset cell and infects other nearby cells, repeating the process

virus may remain dormant within the cell until some factor activates itr and stimulates it to break out of the cell, then enters the lytic cycle

single celled organism

• animal like protists
• do not have chloroplasts
• classified by the way they move:
• amoebas - pseudopods
• paramecium - cillia
• euglena - flagellum

• does not require energy and moves the material fwith the concentration gradient (high to low)
• osmosis and diffusion
• only for small molecules

ability of molecules to move from areas of high concentration to areas of low concentration. Normally involves small uncharged particles like oxygen

• the diffusion of water across a semi0permeable membrane
• causes celss to swell or shrink

• does not require energy, but does require a carrier protein
• example: insulin-needed to carry glucose into the cell