tools of the laboratory #2 Flashcards
metabolism
all chemical and physical workings of a cell
two types of chemical reactions
catabolism
anabolism
catabolism
degradative breaks the bonds of larger molecules forming smaller molecules releases energy
anabolism
biosynthesis process that forms larger macromolecules from smaller molecules requires energy
enzymes
are biological catalysts that increase the rate of a chemical reaction by lowering the energy of activation
simple enzymes
consits of protein alone
apoenzyme
protein portion
cofactors
nonprotein portion
apoenzymes specificity and active site
active site or specific substrate
metallic cofactors
metal ions
coenzymes
organic factors serve as temporary carrier for some substrates vitamins as the most common
exoenzymes
transported extracellularly where they break down large food molecules or harmful chemicals
endoenzymes
retained intracellularly and function there most enzymes are endoenzymes
constitutive enzymes
always present always produced in equal amounts or at rates regardless of the amount of substrate
regulated enzymes
not constantly present production is turned on in response to changes in the substrate concentration
hydrolysis reactions
catabolic reactions that break down large substates into smaller molecules requires the input of water break bonds.
labile
chemically unstable enzymes
denaturation
weak bonds that maintain the shape of the apoenzyme are broken
metabolic pathways
proceed in a stepwise highly regulated manner to maximize the use of a available nutrients and energy
competitive inhibition
substances that resembles the normal substrate competes with the substrate for the active site
allosteric inhibition
form of competitive inhibition in special types of enzymes with two biding sites
allosteric inhibition 2 sites
the active site and the regulatory or allosteric site
noncompetitive inhibition
inhibitor binds to the entire enzyme-substrate complex and prevents the enzyme from complete its action on the substrate
enzyme repression
automatic suppression of enzyme synthesis when end product builds to excess
enzyme induction
enzymes are made only when suitable substrates are present
energy
the capacity to do work or to cause change forms of energy include
redox reactions
always occurs in pairs
metabolic “currency” three part molecule consisting of
adenine a nitrogenous base
ribose a 5 carbon sugar
3 phosphate groups
bioenergetics
study of the mechanisms of cellular energy release
glycolysis
split glucose = pyruvate
Kerbs cycle
a few ATPs CO2
electron transplant chain
ETC series of enzymes using electorns
ATP synthesis 3 different mechanisms
substrate-level phosphorylation
oxidative phosphorylation
photophosphorylation
substrate-level
transfer of phosphate group from a phosphorylated compound directly to ADP
oxidative phosphorylation
series of redox reactions occurring during respiratory pathway
photophosphorylation
in photosynthetic organism utilizing the energy of sunlight
cellular respiration
glucose + oxygen - CO2 + H2O + ATP
aerobic respiration
pathways involved glycolysis, the Krebs cycle electron transport
Products ATP, CO2, H2O
anaerobic respiration
glycolysis the Kerbs cycle ETC molecules other than oxygen are final electron acceptor Nitrate or Sulfur no oxygen produced
fermentation
glycolysis organic compounds are the final electron acceptors lactic acid or ethanol
fermentation
uses organic compounds as terminal electron acceptors.
anaerobic metabolism fermentative
pathways involved glycolysis
produtcs ATP, CO2, ethanol, lactic acid
respiration
pathways involved glycolysis, kerbs cycle, electron transport
products ATP, organic acid, H2S, CH4, N2
many pathways of metabolism are bi-directional or
amphibolic (goes both ways)
photosynthesis
the ultimate source of all the chemical energy in cells comes from the sun
photosynthesis occurs in 2 stages
light-dependent reaction
light- independent reaction
light-dependent reaction
light energy splits water = O2, ATP made
light-independent reaction
do not require light to occur Calvin cycle - ATP used to convert CO2 = glucose
