Biology Unit 5 Cell Energetics IHS Skavaril

Photosynthesis equation

6𝐶𝑂2 + 6𝐻2𝑂 → 𝐶6𝐻12𝑂6 + 6𝑂2

Cellular respiration equation

𝐶6𝐻12𝑂6 + 6𝑂2 → 6𝐶𝑂2 + 6𝐻2𝑂

Cellular respiration

Process where cells turn glucose into ATP

Where does cellular respiration happen

Mitochondria

Matter

Something that you can hold — made of atoms

Energy

Something you cannot hold

What is stored in bonds between atoms

Energy

High energy bonds

Occurs between C-C and C-H bonds

How many phosphate groups does ADP have

Two

How many phosphate groups does ATP have

3

Does ATP or ADP have more energy

ATP

Reactants of photosynthesis

CO2 & H2O

What molecules gives plants material to make glucose

CO2 & H2O

Where does the energy for photosynthesis comes from

Sun

Products of photosynthesis

C6H12O6 (glucose) & O2

Where is photosynthesis performed

The chloroplasts; light dependent reactions in thylakoids, light independent reactions in stroma

What two parts does chloroplasts contain

The thylakoid and stroma

Inputs of light dependent reactions

Energy (red and blue light) & H2O (provides the matter)

Outputs of light dependent reactions

O2

Inputs of light independent reactions

ATP, NADPH, & CO2 (provides the matter)

ATP & NADPH are created from light dependent reactions

Outputs of light independent reactions

G3P & C6H12O6

What provides the energy for light independent reactions to occur

ATP & NADPH

How does NADP+ turn into NADPH

The process of reducing H2O into O2 releases/loses electrons, which is captured by NADP+, turning to NADPH

How does ADP turn into ATP

Some of the energy transferred from the light is used to make ATP

How does NADPH turn back into NADP+

Oxidizing CO2 into C6H12O6 requires electrons, and NADPH gives up its electrons to CO2 for the oxidization process to happen, turning back into NADP+

How does ATP turn back into ADP

As it is being converted back to ADP, it energizes the Calvin cycle, giving it the energy it needs to convert CO2 → C6H12O6

Calvin cycle

The part of photosynthesis where energy (ATP/NADPH) is used to convert CO2 into C6H12O6

Glycolysis

• First step of aerobic respiration

• Does not require oxygen

• Process where one glucose molecule is broken into two pyruvates (3-carbon molecules), releasing some energy

• Occurs in cytoplasm

• Yields NADH (electron carriers) — NAD+ becomes charged takes the energy released from the breaking of the glucose molecule

• Generates 4 ATP but needs 2 ATP = net yield of 2 ATP

Krebs Cycle

• Second step of aerobic respiration

• Requires oxygen

• Process where nutrients (the pyruvates) is taken and broken down to release stored energy

• Occurs in mitochondria

• Yields NADH & FADH2 (electron carriers) — NAD+ & FAD become charged after takes the stored energy released from breaking down nutrients

• Generates 2 ATP

• Waste product/output: CO2

Electron Transport Chain

• Third step of aerobic respiration

• Requires oxygen - final electron acceptor, forming H2O

• Process where activated carriers (NADH & FADH2) donate electrons, creating a proton gradient essential for ATP synthesis, which drives the production of ATP—tldr; stage where energy from food/nutrients is converted into useable ATP

• Occurs in mitochondria

• Generates 28 ATP

• Waste product/output: H2O

How many ATP does one glucose molecule typically yield in aerobic respiration

32 ATP

Alcoholic fermentation

• Done by fungi, bacteria, etc.

• Glycolysis occurs (NAD+ → NADH, ADP → ATP, two pyruvates)

• The two pyruvates will produce CO2 and two ethanol molecules

• NADH is oxidized (lose electrons/releases energy), converting back to NAD+ so glycolysis can occur again

• Occurs in cytoplasm

• Waste product/output: ethanol

Lactic acid fermentation

• Done by cells (e.g. muscle cells)

• Glycolysis occurs (NAD+ → NADH, ADP → ATP, two pyruvates)

• The two pyruvates will produce two lactic acid

• NADH is oxidized (lose electrons/releases energy), converting back to NAD+ so glycolysis can occur again

• Occurs in cytoplasm

• Waste product/output: lactic acid

How many ATP does one glucose molecule typically yield in anaerobic respiration

2 ATP

What are the charged versions of:

1. NADP+*

2. NAD+

3. FAD

4. ADP*
   

BOLD = Electron carriers

* = For photosynthesis (has P in formula)

H in formula = charged carrier

1. NADPH*

2. NADH

3. FADH2

4. ATP*

BOLD = Electron carriers

* = For photosynthesis (has P in formula)

H in formula = charged carrier

What is the end goal of cellular respiration

ATP

What can G3P used to make

All carbon-based molecules

Why is glucose specifically important

It has high energy bonds; the energy in that bond comes from the sun 

What form does carbon go into as in the light independent reaction

CO2

What form does carbon go out as in the light independent reaction

G3P

When it’s hot, plants close their leaf hole, which allow gases to enter the leaf–would more photosynthesis occur or less?

Less photosynthesis because no CO2 can enter the leaf, so there is no building of G3P

Where does energy start in cellular respiration

Glucose

Where does energy end up in cellular respiration

32 ATP

How fast is the breakdown of glucose

Happens slowly over multiple steps

Why does glycolysis and Krebs cycle matter if ETC makes the most ATP

They charge the electron carriers to be able to produce the ATP in ETC