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Bio Exam 3

Terms in this set (75)

cellular respiration
the energy releasing chemical breakdown of fuel molecules and the storage of that energy in a form the cell can use to preform work
ATP and cellular work
chemical energy released by the breakdown of organic molecules during cellular respiration is used to generate molecules of ATP which acts as an energy shuttle, stores energy obtained from food, and releases it later as needed
adenosine triphosphate
THE high energy molecule, phosphate groups have negative charge, phosphate groups like to be free, holds readily available energy for very short periods, donates energy by means of terminal phosphate group
ADP
when ATP is broken down its converted to ADP because of a released phosphate group which releases energy
phosphate transfer
ATP energizes other molecules in cells by transferring phosphate groups to those molecules... this helps cells change shape and enables the transport of ions and other dissolved substances across the membranes and drives the production of the cell's large molecules
ATP cycle
cells spend ATP continuously which is recycled when ADP and phosphate are combined, using energy released by cellular respiration
enzymes
biological catalysts. they regulate the rate of chemical reactions within organisms, lower activation energy, although most enzymes are proteins some types of RNA molecules have catalytic activity as well, work best at a specific temp. and pH, catalyze virtually every chemical reaction that takes place in an organism
metabolism
total of all chemical reactions in an organism but both metabolic reactions require enzymes
activation energy
energy that must be invested to start a reaction but activating the reactants and triggering the chemical reaction, enzymes reduce the amount of activation energy
structure/function
each enzymes recognizes a substrate and the active site has a shape and chemistry that fits each substrate, the ability to function repeatedly is a key characteristic of enzymes
enzyme models
lock and key model or induced fit model
enzyme inhibitors
certain molecules inhibit a reaction by binding to an enzyme and disrupting its function
substrate imposters
enzyme inhibitors can plug up the active site (competitive inhibitors)
penicillin
blocks the active site of an enzyme that bacteria use in making cell walls
ibuprofen
inhibits an enzyme involved in sending pain signals
membrane functions
cells must regulate the flow of materials to and from the environment
plasma membrane
consists of a double layer of fat (phospholipid bilayer) with embedded proteins, most important role is regulation
passive transport
diffusion of a substance across a membrane without the input of energy
facilitated diffusion
a type of passive transport because it does not require the cell to expand energy
diffusion
movement of molecules spreading out evenly into the available space --> lower concentration
osmosis
diffusion of water across a selectively permeable membrane
isotonic solution
equal solute concentration as the cell's interior
hypertonic solution
displays higher solute concentration than the cell's interior
hypotonic solution
displays lower solute concentration than the cell's interior
osmotic pressure
concentration of dissolved substances in a solution
osmoregulation
regulation of water balance
active transport
molecules (solutes) move from an area of a low to high concentration which requires a carrier in the membrane, energy, and ATP ---> requires a cell to expend energy to move molecules across a membrane
exocytosis
movement of materials out of the cytoplasm of a cell via membranous vesicles or vacuoles that fuse with the plasma membrane
endocytosis
a cell takes materials in
photosynthesis
(autotrophs) plants convert the energy of sunlight to the chemical energy of sugars and other organic molecules
autotrophs
"self feeders" or producers make organic compounds from things that are inorganic
heterotrophs
consumers, humans and other animals
cellular respiration
aerobic (requires O2) harvesting of chemical energy from organic fuel molecules (food into ATP) and has waste products of H2O and CO2 --> similar to photosynthesis
fuel molecule used by cell
glucose (simple sugar)
3 stages/chemical reactions of cellular respiration
glycolysis, citric acid cycle, and electron transport
glycolysis
1 a molecule of glucose is split into two of a compound called pyruvic acid usually located in the cytoplasm (no O2 needed)
citric acid cycle (krebs cycle)
2 uses enzymes that are dissolved in the fluid within mitochondria and completes the breakdown of glucose/acetic acid to CO2
electron transport
3 electrons captured from food by NADH are stripped of their energy until they are finally combined with O to create H2O which produces ATP, proteins and other molecules that make up electron transport chains are imbedded within the inner membrane of the mitochondria
cellular respiration chemical reaction
glucose and O --> CO2 and H2O (up to 32 ATP for each glucose)
aerobic respiration
takes place in the cytosol = glycolysis
takes place in mitochondria = form. of acetyl CoA, citric acid cycle, and electron transport
pyruvic acid
cannot be used by the citric acid cycle unless it is transformed so it loses a C as CO2 and becomes acetic acid (2 C), electrons are stripped from these molecules and transferred to NAD+ which becomes NADH
ATP synthase
(e transport) is constructed by proteins built into the inner mitochondrial membrane next to the proteins of the electron transport chains
fermentation
is the anaerobic harvest of food energy
fermentation in muscles
relies on glycolysis to produce ATP, to harvest food energy during glycolysis NAD+ must be present to receive electrons (cannot occur in anaerobic conditions) pyruvic acid produces a waste of lactic acid which is transported to the liver and turned back to pyruvic acid
fermentation in microorganisms
lactic acid produced by yeast can make yogurt, cheese, sour cream, soy sauce, pickles, cabbages, olives, sausage meat products, and alcohol
photoautotrophs
use sun energy from light
chemoautotrophs
use chemical energy that use sulfide or methane
sunlight
type of energy called radiation or electromagnetic energy
wavelength
the distance between the crests of two adjacent waves
electromagnetic spectrum
full range of radiation
nature of sunlight
when sunlight shines on pigmented material, certain wavelengths (colors) of the visible light are absorbed and disappear from the light that is reflected by the material
anabolic
small molecules combined
endergonic
stores energy
chloroplasts
light absorbing organelles found in interior cells of leaves, has a double membrane envelope with an inner membrane full of stroma (think fluid) suspended in the stroma are sacs called thylakoids and thylakoids are stacks called grana
stoma
pores in a plants cuticle through which water vapor and gases are exchanged
chloroplast pigments
selective absorption of light by leaves explains why they appear green to us (THEY REFLECT)
chlorophyll molecules
located in the thylakoid membranes, contain magnesium in the center of their porphyrin ring and harvest energy by absorbing wavelengths (most importantly blue and red)
chlorophyll A
participates directly in light reactions and absorbs blue-violet and red wavelengths
chlorophyll B
very similar to A but absorbs mainly blue and orange light and conveys energy to chlorophyll A
carotenoids
absorb mainly blue-green light, absorb and dissipate excessive light energy that might damage chlorophyll
beta-caroteniods
bright orange/red pigment found in pumpkins, sweet potatoes, and carrots and is converted to vitamin A in the body
lycopene
bright red pigment found in tomatoes, watermelons, and red peppers. Is an antioxidant that is being studied for potential anti-cancer properties
photosynthesis process
carbon dioxide + water --light energy--> glucose+ oxygen gas
light dependent reaction
requires light, produces energy from light(photons) in the form of ATP and NADPH, gives off O2
light independent reaction
uses energy (ATP and NADPH) from light reactions to make glucose
carbon fixation
the initial incorporation of carbon from the atmosphere into organic compounds
photosystems
electron transport chain that connects transfer electrons form H2O to NADP+, producing NADPH
first photosystem
photon excite electrons in the chlorophyll, these protons are trapped in primary acceptor and then replaces the lost electron by extracting new ones form water. releases O2
second photosystem
energized electrons form the first photosystem and passes down electron transport chain and makes ATP, transfer light-excited electrons to NADP+ to make NADPH
calvin cycle inputs
CO2 from the air, ATP and NADPH produced by light reactions
calvin cycle outputs
G3P is produced then used to make glucose and other organic compounds
stroma
thick fluid in the inner membrane
thylakoids
interconnected membranous sacs suspended in the stroma
granum
thylakoids concentrated in the stacks
stoma
pores in a plants cuticle through which water vapor and gases are exchanged between the plant and the atmosphere
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