concept 8.3: ATP powers cellular work by coulping exergonic reactions to endergonic reactions

what three main kinds of work does a cell do

chemical work, transport work, mechanical work

chemical work

driving endergonic reactions like creating polymers from monomers

transport work

pumping substances against the direction of spontaneous movement

mechanical work

beating of cilia or muscle contractions

what is most energy in cells mediated by

most energy in cells is mediated by the energy molecule ATP

what does ATP stand for

adenosine triphosphate

how do cells do work

by energy coupling and using exergonic process to drive an endergonic one

describe the composition of ATP

composed of ribose (a sugar), adenine (a nitrogenous base) and three phosphate groups

what does ATP function as

energy coupling and as one of the nucleoside triphosphates used to be RNA

what process can break the bond between the phosphate groups of ATP’s tail

hydrolysis

the bonds between phosphate groups in ATP can be equated to what?

they have a lot of potential energy, they are like a compressed spring

how much energy is released when the terminal phosphate bond in ATP is broken

delta G= -7.3 kcal/mol

when is energy released from ATP

when the terminal phosphate bond is broken

what does the hydrolysis of ATP yield

ADP + P_i (inorganic phosphate) and energy

is the product of the hydrolysis of ATP at a lower or higher energy state

ADP and P_i are at a lower energy state than ATP

where does the energy come from when ATP is hydrolized

from the chemical change to a state of lower free energy in the products

what is powered by ATP hydrolysis

cellular work including mechanical, transport, and chemical

is hydrolysis endergonic or exergonic

hydrolysis of ATP is endergonic

hydrolysis of ATP is (endergonic/exergonic) and it drives (endergonic/exergonic) reactions

hydrolysis of ATP is endergonic and it drives exergonic reactions

phosphorylation

the transfer of a phosphate group from ATP to another molecule

what is a phosphorylated intermediate

it is the molecule that receives the transferred phosphate group from ATP

what does a phosphorylated intermediate allow for

it allows for the coupling of exergonic and endergonic reactions

describe a phosphorylated intermediate compared to its original molecule

more reactive, less stable, and with more free energy

what is transport and mechanical work in a cell powered by

they are both powered by ATP hydrolysiss

what does the hydrolysis of ATP do to protein

it alters protein shape and in turn its binding ability to another molecule

why does the hydrolysis of ATP help transport molecules productivity

they can shift the protein structure and move the item that is bound to it to the other side of a barrier

why does rigor mortis occur

because the cells no longer have any ATP or energy

what does ATP do for motor proteins

they provide energy for their movement

how can ATP be regenerated

by adding a phosphate group to ADP (adenosine diphosphate)

where the energy to phosphorylate ADP come from

catabolic reactions in the cell

what is the ATP cycle

the shuttling of inorganic phosphate and every and coupling energy yielding catabolic processes to energy consuming anaolic ones