Photosynthesis and Respiration

Category: Biology Education

Tags: Autotrophs and HeterotrophsBiologyCellular RespirationEnergy CapturePhotosynthesis

Entities: ATPAutotrophsCalvin cycleChemosynthesisElectron transport chainFermentationHeterotrophsMitochondriaMr. AndersonNADPHPhotosynthesisRespiration

Transcript

00:00

[Music] hi it's Mr Anderson and welcome to biology Essentials video 13 this is on free energy capture and storage but what you'll quickly learn is that this is mostly about

00:16

photosynthesis and this is actually a map of photosynthesis on our planet so what you could see this is both on land and on the ocean you'll see that photosynthesis is going to be highest in areas like here South America uh that be the Amazon uh or Eastern uh North

00:33

America or you'd find it in a lot of uh northern Europe and Northern Asia um and so it's mostly about photosynthesis oh and we also see it in the oceans so we're going to see a ton of it near the equator but not exactly at the equator and I imagine that has to do with the currents um the other thing it's going

00:50

to be about is going to be about respiration and so I'm going to try to get through the whole thing on photosynthesis and respiration if it seems like I'm going too fast or it's not understandable I've made a video on both photosynthesis and INSP respiration individually um and so take a look at

01:06

those and I I hope that'll be helpful um so what am I going to talk about in this well just like in the last podcast I'm going to talk about how life uses free energy the goal of life is to make ATP so we can use energy now there's two Life Strategies there's the life strategy of the autot trofes an example

01:22

would be a plant those are things that make their own food um and then the heterotrophs and an example would be you and you're a atro that means you eat your own food and so autotrophs on our planet mostly use photosynthesis so they take energy from the Sun in both the

01:38

light reaction and the Calvin cycle to make sugars or to make macromolecules that they can use there's a a obscure group of organisms on our planet that don't have light available and it doesn't mean that they're out of lock they use chemosynthesis so they they use the energy found in chemicals to

01:54

actually make their food um the other lifestyle then is heterotrophs heterotrophs are going to to um use cellular respiration which is essentially oxygen mitochondria sugar and they're going to make uh make ATP from that um it requires oxygen which

02:10

pulls on those electrons we'll talk about that in a second and the process is glycolysis KB cycle and then finally the electron transport chain if you don't happen to have oxygen um you can also use a process called fermentation and I'll explain that now the thing that

02:26

I really haven't talked about oh I haven't talk I'll talk about Evolution as well but the one thing that I want to make sure that you understand is that autot Tres aren't making the food for us they're making the food for themselves and so not only does a plant do photosynthesis they then use cellular

02:43

respiration um to actually break the energy and and get the energy out of the food that they ended up making and so this kind of summarizes that cycle um so what we have are the the way of the heter they take organic molecules and oxygen and they use that to make carbon

02:58

dioxide and water we call that that Pro cellular process cellular respiration and then autot tropes will actually convert that back into organic molecules so they can then utilize that energy and so most of those on our planet use photosynthesis like plants uh and most

03:13

of the heterotrophs use cellular respiration example be like a cheetah but I do want to briefly talk about chemosynthesis chemosynthesis occurs where there's not a lot of light on our planet where's a great example of that deep dark in the ocean uh and so these are giant tube worms which can get

03:30

something like 21 ft long so pretty ridiculous um but these tube worms actually have uh right here this portion um where they're actually taking in carbon dioxide taking in oxygen taking in hydrogen sulfide gas from these black

03:46

smokers which is just uh organic material coming out of a situated over a hot spot and what they're doing is feeding bacteria that live in their gut those bacteria that live in their gut are actually taking that hydrogen sulfide gas and they're utilizing the energy from that to make simple

04:01

carbohydrates and so they don't require light at all they're actually making sugars using uh powers of the chemicals um another example of that is what if you don't have oxygen well you can use a process called fermentation and so this is how wine is made uh it's a barrel that they've actually cut in half and so

04:17

these are yeasts that are would die because you're you're not letting them get any Oxygen but they can actually do alcoholic fermentation to survive uh until they eventually die um we use something called lactic acid fermentation to do the same thing it's a form of uh energy um capture um but we

04:36

don't require oxygen to do it okay so let's talk about photosynthesis and respiration so this is U my animation for how photosynthesis works and the one thing that you want to always the problem when you're doing photosynthesis and respiration is that you get so into the steps that you don't

04:52

really understand what's going on you miss the forest for the trees and so what we're doing in photosynthesis is taking carbon dioxide plants take that in taking water converting that to glucose and eventually to oxygen and so if I animate it it looks like this and

05:08

so what we're doing is we're taking the carbon in carbon dioxide and we're actually turning that into carbon in uh glucose we're releasing oxygen as a waste product but what we're really doing is we're storing energy in this glucose molecule the Delta G or the free

05:26

energy is positive that means that we're storing energy in that glucose molecule we're actually storing it in these bonds right here between the carbon and the hydrogen now it's not as simple I wish it was it's not as simple a chemical reaction as this it's actually pretty complex um but what I don't want you to

05:43

miss is I don't want you to miss what happens to the carbon dioxide what happens to the water and how does that convert into glucose and and oxygen and so if you've missed that then I've done a b bad job okay whenever I'm thinking about photosynthesis I actually break it down into the two words so I can

05:58

remember the different parts the photo part is the light reaction and photo means light and synthesis means to build and so that's going to be the Calvin cycle and so the photo part or the light reaction is going to take place the whole thing takes of photosynthesis takes place in the chloroplast and

06:14

here's a bunch of chloroplast inside a plant cell but the light reaction is going to take place right here it's in the thid membrane and if we have a bunch of thid membrane stacked up and we call that whole thing a granum so what happens in the light reaction we take in water we take in light and we release

06:32

oxygen and then we store that energy in ATP and nadph the next step is the Calvin cycle Calvin cycle where does that take place well that takes place in this liquid portion inside the chloroplast that's called the stroma and in the Calvin cycle we're going to take the energy of

06:48

ATP and nadph and we're going to take carbon dioxide and we're actually going to make sugars out of it and so in summary that's what photosynthesis is it's taking in energy in the form of of light and eventually storing that energy in sugars so what is that uh Sugar We're

07:04

talking about glucose like I just mentioned a second ago now the actual process is is not that simple and so the light reaction is where you should spend most of your time trying to figure out photosynthesis and so where are we we are in the thid membrane so this is going to be inside the chloroplast

07:20

itself and so what we get is light and that light is going to come into photosystem 2 and photosystem one inside here we have chlorophyll chlorophyll is a a magical pigment that can absorb light energy and get excited and pass that excitement on in the form of

07:37

electrons and so the first thing that happens let me change color is that light comes in and that gets the chlorophyll excited um it also is going to pass an electron down an electron transport chain so let's follow where

07:53

that electron goes it eventually goes to nadph and so that electron that goes down this electron transport chain has to come from somewhere and so where is it coming from it actually comes from the water so again what is another thing that we need in the light reaction we

08:08

need water and so the energy is coming from that or the electrons coming from the water that's splitting water and it's splitting water into oxygen so oxygen remember is one of the products that we give off in photosynthesis that's what you're breathing right now

08:25

um but we also create protons protons are simply hydrogen atoms that have lost their electrons and I'll get back to those in a second so let's track those electrons again so the electrons are flowing through an electron transport chain in the thilo covid and as they go

08:40

through these proteins which I don't ever want you to memorize the names of as they go through these proteins what they're doing is they're using their energy to actually pump protons to the inside of the thyo covid membrane and so what we're doing is we're moving protons

08:55

to the inside of this membrane so we're in increasing the number of protons inside here so we're making it really positive on the inside of that thid membrane now the protons have nowhere to go the only way that they can go is out through

09:11

another protein which is called ATP synthes and so it uses the energy of those flowing protons to actually make our friend ATP and so let's track what we got we got light coming in we've got water uh breaking down into oxygen to

09:28

give up its electron and now we've made nadph that's where the electrons end up and then ATP so we've stored the energy of that light in ATP and nadph now what do we use that light to do well Melvin Calvin who

09:44

invented not but discovered the Calvin cycle uh shows the process that happens next so essentially what you do is you take in carbon dioxide so plants take that in through their stomata they then use the energy of ATP and nadph to convert that into uh sugar and so this

10:02

is a g3p molecule um but essentially we can use that to make uh sugars inside a plant and so all these intermediary uh chemicals you don't need to know what you do need to know is that we make ATP and nadph so we can use the energy of that um to actually make uh sugars now

10:20

where does the um celvin Cycle takes place Kelvin cycle is going to take place in the stroma or the liquid portion of the cell so that's we store our energy in um sugar the evolution of that in our planet we think happened really early so we think those first

10:37

life forms on our planet we're actually using some form of photosynthesis um maybe chemosynthesis to begin with but we do know this that about two billion years ago and we look at the rock layer this rock is about 2.1 billion years ago um we start to see red

10:54

showing up and red bands showing up and what that indicates is that oxygen is being produced at appreciable amounts and so this right here is actually a graph of atmospheric oxygen through time so here we are today and this is for the last you know 3.8 billion life on our

11:11

planet we see that the amount of oxygen is increased and these two lines here are just the guesses that scientists have uh kind of a high low guess and so we know that the oxygen levels on our our planet have increased over time where did that oxygen come from it

11:28

actually came from photo synthesis okay next let's go to cellular respiration what happens in cellular respiration cellular respiration we're actually using the energy in those sugars so in glucose in the presence of oxygen we're breaking that down into carbon dioxide and water and we're releasing energy

11:44

from that so let's see what that looks like so we break down that glucose that's a exergonic reaction we're releasing energy we're making carbon dioxide we're making water but we're mostly making energy in the form of at TP that we can use again it's not as

12:01

simple as this so let's get to uh what respiration really looks like and how it where it takes place and in order to do cellular respiration you need a mitochondria and you also need one more thing you need O2 you need oxygen so the parts of the mitochondria that you

12:16

should become familiar with uh first of all we've got an outer membrane outer membrane is going to be this portion right here we also have an inner membrane so it looks like that uh we have an inner membrane space the inner membrane space is going to be right

12:32

between the outer and the inner membrane and you see here that we have these folds that go on uh the inside of that inner membrane and what that does is increase the surface area but the last thing that we should become familiar with is actually called uh The Matrix Matrix is going to be the inside of the

12:47

mitochondria and so the parts of cellular respiration the first part is called glycolysis that'll actually take place out here next thing is going to be the kreb cycle KB cycle will take place in here that's in the Matrix and then finally we

13:02

have the electron transport chain electron transport chain is going to take place along that inner membrane uh and so the reason we have that folds is to increase surface area now this looks a little scary the diagram but it shouldn't be that scary because we're going to miss all the intermediates so

13:17

what do we start with glucose and we break that down into perate one thing that you should know is that glucose is a six carbon molecule and uh down here at perate we have two three carbon molecules uh we release a little bit of ATP and glycolysis and that takes place

13:34

outside of the mitochondria next we enter into the kreb cycle and the kreb cycle we're going to take that carbon which is in perate and we're going to release that as carbon dioxide but the important thing we're doing in the kreb cycle is we're storing energy we're storing energy as nadh uh NAD and fadh2

13:53

or fad so we're storing the energy that was found in the perate in NAD and fad so we can finally use that in the electron transport chain let's look at what happens in a little more detail as far as the electron transport chain we've stored energy now in NAD and we've

14:10

stored energy in fad we're going to transfer that energy in the form of electrons just like in photosynthesis we've now got an electron transport chain it's not an ethoid it's the inner membrane but as we transfer that electron through the electron transport

14:25

chain we're pumping protons to the outside of the inner membrane so it's now in this inner membrane space we now have a buildup of all this positive charge here the only place it can go is through our friend ATP synthes and we eventually make ATP so that energy that

14:42

you use right now that energy that you're using to think to move um all of the actions that ATP comes from that flow of those protons through here now the puzzle is not quite Complete because we've dropped off that energy of NAD uh H and

14:57

fadh2 Well's follow what happens to that electron that electron is eventually going to combine with oxygen and hydrogen and we're going to make H2O and so who's pulling that electron the whole way our friend oxygen oxygen is pulling

15:13

that electron towards it it's highly Electro negative and when it finally gets to it we've made our product we've made our H2 H2O which is given off but more importantly we've made ATP and we've made energy through this process of cellular respiration so photosynthesis and respir a or how we

15:30

utilize energy free energy from the Sun uh to make ATP to make ourselves grow uh so I hope that's helpful