Energy & Metabolism (PPT 9-10) (U1) Flashcards
What is the formula for photosynthesis?
carbon dioxide + water ——> glucose + oxygen + water
Arrow is the light energy
What is the chemical equation for photosynthesis?
6CO2 + 12H2O ——> C6H12O6 + 6O2 +6H2O
What do cells need energy for?
- Active transport
- Synthesis of materials
- Metabolism
- Eliminating wastes
- Manufacture & repair of organelles
- Reproduction that involves synthesis of new membranes
Can energy be created or destroyed?
No, but it can be changed from one form to another.
What are some of the forms energy can come in?
- Light
- Electrical
- Heat
- Chemical
Ultimately, where does all energy originate from?
The sun
What is chemical energy?
Chemical energy is the energy stored within the bonds between atoms.
How is chemical energy released?
When these bonds between atoms are broken.
What would happen if Glucose was broken down in one big reaction?
The energy released would be dangerously large for the cell. Most of it would be lost as the cell could not harness it.
How does the cell transport energy?
Through special energy carriers that hold small packets of useable energy.
How is ATP formed?
ATP is formed by adding a phosphate group called ADP. This energy comes from the breakdown of glucose.
How does ATP work?
It is an energy carrier (like a FedX van). A molecule with a high energy terminal phosphate bond that is easily broken to release a small packet of energy.
Does it cost energy to recharge ADP?
Yes, but vert little compared to the amount required to create a whole new ATP molecule.
What do Autotrophs have?
- Ability to synthesis organic molecules from inorganic once.
What are the two types of Autotrophs?
1- Those that make glucose during photosynthesis.
2- Some prokaryotes use chemosynthesis
Plants have the ability to…? (Finish the sentence)
Harness and trap the light energy from the sun and convert it into chemical energy in the for of glucose.
What is chemosynthesis?
Some autotroph bacteria trap their energy by chemical reactions. (Using chemicals)
What are Heterotrophs? What can’t they do?
Animals are unable to use inorganic compounds to make glucose. They get the organic compounds they need by eating other organisms.
What is photosynthesis in a nutshell?
1- Light energy is trapped by chlorophyll
2- Used to form ATP molecules by splitting H2O.
3- These ATP molecules are then used to drive carbon dioxide fixation.
What is chlorophyll?
A green pigment molecule.
Where does photosynthesis occur?
In specialised photosynthetic cells that contain lost of chloroplasts.
What does the chloroplast consist of?
Many internal layers of inner membranes that form sacs of thylakoids called grant and a fluid stroma.
ESQ: Like the mitochondria, the chloroplast is an efficiently designed manufacturing organelle which carries out a series of metabolic reactions that are catalyzed by enzymes. Explain what makes it so efficient and why it’s well designed for the task.
IDK
What happens in photosynthetic bacteria?
The reactions of photosynthesis take place within the cell itself, not a discrete organelle.
What are the two steps involved in photosynthesis?
1- The splitting of water using the energy from the sun.
2- The manufactacture of glucose.
Name some factors that affect the rate of photosynthesis?
- Number of chloroplasts present
- Supply of reactants
- Conditions surrounding the reaction
How do cells get energy to make ATP in respiration?
From ADP, by breaking apart glucose.
What is cellular respiration all about?
Converting chemical energy stored in glucose and converting it to a form the cells can use.
What are the three stages of cellular respiration?
1) Glycolysis
2) The Krebs cycle
3) The Electron Transport Chain (ETC)
Where does the first stage of respiration occur?
In the cytosol (liquid part of the cell)
Where do the 2nd and 3rd stage of respiration occur?
These stages occur in the mitochondria, but ONLY if oxygen is present.
What is the fundamental purpose of respiration?
To harness energy in the form of ATP.
What is Glycolysis?
- The first stage of respiration
- The splitting of glucose
Where does glycolysis occur? & Does glycolysis require oxygen?
- Glycolysis occur in the cytosol (liquid part of the cel)
- No, this stage does not require oxygen
What is the fundamental purpose of glycolysis?
To split large 6C molecules into smaller, manageable 3C molecules with the bonus of some ATP produced.
What is the 2nd stage of respiration and where does it occur?
- Aerobic respiration
- Occurs in the Mitochondria among the cristae (folds).
Why does Aerobic respiration occur in the Mitochondria?
Because the enzymes required for these reactions are found embedded in the convoluted membranes.
How does Aerobic respiration occur?
In a series of steps called the Krebs cycle and the Electron transport chain (ETC)
What are the stages of the Krebs cycle?
1) Each 3C molecule is broken down to form CO2, Hydrogen ions, electrons, & energy.
2) Hydrogen & electrons carved by NADH and FADH2.
3) These molecules are transported to the mitochondria.
4) 2 more ATP molecules are formed.
What is the fundamental purpose of ETC?
To make a lot of ATP. `
How much ATP is formed in the electron transport chain?
32 ATP molecules.
What are the inputs for respiration?
- Glucose (Glycolysis)
- 6O2 (ETC)
What are the outputs of respiration?
- 602 (Krebs cycle))
6H2O (ETC)
36 ATP (2 Glycolysis, 2 Krebs cycle, 32 ET Chain)
What happens if oxygen is in short supply?
Glycolysis will occur as it does not require oxygen. Without oxygen, cells use the anaerobic respiration pathway called fermentation.
During fermentation in animal cells, pyruvate is converted… (Finish the sentence)
into lactic acid.
During fermentation in plant cells, pyruvate is converted… (Finish the sentence)
into CO2 and alcohol.
What is the point of converting pyruvate if no ATP are formed?
If the cell didn’t convert this, the quantities of pyruvate would increase, therefore slowing the glycolysis reaction.
How do you measure the rate of cellular respiration?
1) Measure the rate the reactants disappear
2) Measure the rate the products are formed.
During Fermentation, where do the processes take place?
All take place in the cytoplasm without oxygen.
What factors affect the rate of cellular respiration?
- Reactant availably (e.g. glucose & oxygen)
- Temperature
