confused with atp, glucose and adp

is atp a energy carrier and adp the actual release of energy. so in aerobic respiration, when energy is released would that be adp. if so, where does the tap come from. i know that it is an intermediate energy store but i thought that glucose was the source of energy. wouldn't glucose and atp be the same thing?

Reply 1

h3rmit

15

Original post by esmeralda123

is atp a energy carrier and adp the actual release of energy. so in aerobic respiration, when energy is released would that be adp. if so, where does the tap come from. i know that it is an intermediate energy store but i thought that glucose was the source of energy. wouldn't glucose and atp be the same thing?

The energy comes from hydrolysing a phosphanhydride (phosphate-phosphate) bond in the ATP - ADP is more of a byproduct, whose only use regarding energy is to be used to make more ATP.

ATP is an energy source too, and a more immediate one than glucose. ATP is a lot easier to use for small amounts of immediate energy than glucose, which has to go through several steps of respiration.

Reply 2

debbie394

OP

11

Original post by h3rmit

The energy comes from hydrolysing a phosphanhydride (phosphate-phosphate) bond in the ATP - ADP is more of a byproduct, whose only use regarding energy is to be used to make more ATP.

ATP is an energy source too, and a more immediate one than glucose. ATP is a lot easier to use for small amounts of immediate energy than glucose, which has to go through several steps of respiration.

wouldn't you need energy for hydrolysis, where does this come from?

Reply 3

h3rmit

15

Original post by esmeralda123

wouldn't you need energy for hydrolysis, where does this come from?

The bonds are quite weak, but some energy is required. You get a lot more energy out than in, however, and enzymes can catalyse ATP hydrolysis to lower the activation energy.

Reply 4

debbie394

OP

11

Original post by h3rmit

The energy comes from hydrolysing a phosphanhydride (phosphate-phosphate) bond in the ATP - ADP is more of a byproduct, whose only use regarding energy is to be used to make more ATP.

ATP is an energy source too, and a more immediate one than glucose. ATP is a lot easier to use for small amounts of immediate energy than glucose, which has to go through several steps of respiration.

if glucose and ATP are both energy sources, then what does this statement mean: aerobic respiration makes 38 molecules of ATP per glucose molecule

i can't get my head around what it means
does this just say that glucose is used to make ATP
if so, what makes ATP

Reply 5

Reality Check

22

Original post by esmeralda123

if glucose and ATP are both energy sources, then what does this statement mean: aerobic respiration makes 38 molecules of ATP per glucose molecule

i can't get my head around what it means
does this just say that glucose is used to make ATP
if so, what makes ATP

You seem very confused with all this. I suggest you revise glycolysis, what exactly ATP is and preferably electron carriers and their roles (NAD/FAD).

ATP is 'made' from ADP plus inorganic phosphate, Pi. Aerobic respiration results in synthesis of a net total of 38 molecules of ADP for each glucose molecule which is oxidised thereby. Glucose is used as a substrate - a source of energy. This energy, from rearranging the bonds into different intermediate compounds and other transformations, is channeled into making ATP from ADP + Pi. It's a bit like plugging your kettle in - you're using the energy (the electricity) to do another task (boiling the water). Does that make sense?

(edited 7 years ago)

Reply 6

debbie394

OP

11

Original post by Reality Check

You seem very confused with all this. I suggest you revise glycolysis, what exactly ATP is and preferably electron carriers and their roles (NAD/FAD).

ATP is 'made' from ADP plus inorganic phosphate, Pi. Aerobic respiration results in synthesis of a net total of 38 molecules of ADP for each glucose molecule which is oxidised thereby. Glucose is used as a substrate - a source of energy. This energy, from rearranging the bonds into different intermediate compounds and other transformations, is channeled into making ATP from ADP + Pi. It's a bit like plugging your kettle in - you're using the energy (the electricity) to do another task (boiling the water). Does that make sense?

i know that ATP consists of three inorganic phosphate groupsbut isn't Pi an organic phosphate

Reply 7

Reality Check

22

Original post by esmeralda123

i know that ATP consists of three inorganic phosphate groupsbut isn't Pi an organic phosphate

No - the 'i' in Pi is a bit of a clue that it's inorganic.

As I said in my earlier post, I don't want to sound rude but I really think you need to go back to brass tacks and revise this topic from the start. This is pretty basic stuff, and you do need to have a solid grasp of the basics, such as how the glucose molecule is oxidised, how AMP/ADP and ATP differ, what role NAD and FAD play and the differences between glycolysis, the Kreb's Cycle and oxidative phosphorylation. It's a slightly tricky topic, but nothing that hard work can't solve :smile:

Reply 8

debbie394

OP

11

Original post by Reality Check

No - the 'i' in Pi is a bit of a clue that it's inorganic.

As I said in my earlier post, I don't want to sound rude but I really think you need to go back to brass tacks and revise this topic from the start. This is pretty basic stuff, and you do need to have a solid grasp of the basics, such as how the glucose molecule is oxidised, how AMP/ADP and ATP differ, what role NAD and FAD play and the differences between glycolysis, the Kreb's Cycle and oxidative phosphorylation. It's a slightly tricky topic, but nothing that hard work can't solve :smile:

do you think i need to know that for as level ocr a biology, because my book only says how energy is released from ATP? I just wanted to get a deeper understanding. i know it will be good if i do some extra reading on it but do you think its likely to be mentioned in my exams (i know that the harder questions require more thought) or is it something that isn't necessary for this year ?
thank you for ur help :smile:

Reply 9

h3rmit

15

Original post by esmeralda123

do you think i need to know that for as level ocr a biology, because my book only says how energy is released from ATP? I just wanted to get a deeper understanding. i know it will be good if i do some extra reading on it but do you think its likely to be mentioned in my exams (i know that the harder questions require more thought) or is it something that isn't necessary for this year ?
thank you for ur help :smile:

Technically, you only need it next year. It's easier to remember things with comprehensive knowledge though

Original post by esmeralda123

if glucose and ATP are both energy sources, then what does this statement mean: aerobic respiration makes 38 molecules of ATP per glucose molecule

i can't get my head around what it means
does this just say that glucose is used to make ATP
if so, what makes ATP

Haven't you answered your own question here?

Reply 10

Reality Check

22

Original post by esmeralda123

do you think i need to know that for as level ocr a biology, because my book only says how energy is released from ATP? I just wanted to get a deeper understanding. i know it will be good if i do some extra reading on it but do you think its likely to be mentioned in my exams (i know that the harder questions require more thought) or is it something that isn't necessary for this year ?
thank you for ur help :smile:

You're welcome :smile:

I don't know the OCR specification, but I know for AQA this topic only comes up in detail in A2. At AS, I think it's sufficient to know about the concepts of cellular respiration in a broad-brush sense, i.e. what the substrates are and roughly how they are broken down and maybe with carrier proteins and active transport.

You will do this topic in detail, but that will be in your next, A2 year. What context are you reading this stuff - i.e. what's the book chapter. Basically, don't do a load of work now which is 'to come' - this topic builds on stuff you're learning this year (e.g. the structure of macromolecules like glucose). If you try to do it all now, you'll just confuse yourself because you're putting the cart before the horse. Well done, though, for trying to go a bit deeper with things.

Does this help you?

(edited 7 years ago)

Reply 11

Davwardo

3

I know it may seem irrelevant but in Northern Ireland with CCEA exam board, the entire process of glycolysis and energy production is A2 (as it is with AQA it seems)
But to keep things simple enough, Glucose is a molecule used in respiration to is used to create ATP. The glucose undergoes reactions and will create ATP (adenosine TRIphosphate) from ADP (Adenosine DIphosphate)
When energy is needed ATP will undergo a reaction that will remove the inorganic phosphate (Pi) and release about 38kj of energy.
As for the other question

Original post by esmeralda123

if glucose and ATP are both energy sources, then what does this statement mean: aerobic respiration makes 38 molecules of ATP per glucose molecule

i can't get my head around what it means
does this just say that glucose is used to make ATP
if so, what makes ATP

The glucose is used at the start of the process of respiration (which has 4 stages, you may not need to know this but they are Glycolysis, link reaction, kreb cycle, and electron transport carrier) One glucose molecule will undergo reactions to become other compounds that are used throughout to create 38 molecules of ATP.

Thats the simplest thing way of explaining, is what I said to help a friend- hopefully I haven't confused you.

confused with atp, glucose and adp

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