Bio Final Exam Hassan (24-25/Freshman year)

What is Cellular Respiration?

-step by step break down of high energy glucose molecules to release energy

-take place day and night in all living cells

-occurs in stages; controlled by enzymes

Which organelle does cellular respiration occur in?

mitochondria

Aerobic

-process that requires oxygen

Anaerobic

-process that doesn't requires oxygen

Which type of cellular respiration releases large amounts of energy?

-aerobic

How many stages are there in cellular respiration?

3 stages

What are the 3 stages of cellular respiration?

1. glycolysis

2. krebs cycle (citric acid cycle)

3. electron transport chain (ETC)

What does glycolysis mean?

-"splitting sugars"

What happens in glycolysis?

Glucose (6 carbon) is broken down into 2 pyruvic acid (3 carbon)

Where does glycolysis occur?

-in the cytoplasm

Does glycolysis require oxygen?

No

How much ATP does glycolysis produce?

net gain of 2 ATP (makes 4, but 2 used)

What is the second stage of Cellular Respiration?

Krebs cycle (citric acid cycle)

Where does the Krebs cycle occur?

mitochondrial matrix

Is the Krebs Cycle aerobic? (Does it require oxygen)

Yes

What happens in the Krebs Cycle? (Brief summary)

-pyruvate is broken down into carbon dioxide in a series of energy-extracting reactions -it produces the electron carriers NADH and FADH2 and also CO2 -net yield of 2 ATP -enzymes use: CoA (it helps pyruvate enter the cycle)

How much ATP does the Krebs Cycle generate?

2 ATP

What is the 3rd stage of cellular respiration?

electron transport chain (ETC)

Where does the ETC occur?

inner mitochondrial membrane

Is the ETC aerobic? (Does it require oxygen)

Yes

How much ATP does the ETC produce?

32-34 ATP

What happens in the ETC (cellular respiration)? (Brief Summary)

-electrons from NADH and FADH2 move through a series of protein complexes -the energy from the electrons creates a high H ion (H+) concentration -this high concentration power ATP synthase to make ATP -oxygen accepts the electrons and a H+ to make water

Aerobic Cellular Respiration Equation (words)

glucose + oxygen → carbon dioxide + water + energy

Aerobic Cellular Respiration Equations (symbols)

C6H1206 + 6O2 → 6CO2 + 6H2O + 36-38 ATP

When does Anaerobic respiration occur?

Lack of oxygen

What happens to glucose during anaerobic respiration?

glucose is broken down incompletely & less energy is transferred

What happens to most of the energy produced during anaerobic respiration?

-it is lost as heat

What organisms preform Lactic Acid Fermentation?

-animal muscle cells -some specialized bacteria (used to create yogurts, some cheeses, sour cream etc)

What organisms preform Alcoholic Fermentation?

-yeast -some bacteria

What is an example of a glucose source for Alcoholic Fermentation?

-grapes

What are the outputs of glycolysis?

2 pyruvate, 2 ATP, 2 NADH

What are the outputs of the Krebs Cycle?

2 ATP, 2 FADH2, 8 NADH, 6 CO2 (amount of NADH and FADH2 aren't important)

What are the outputs of the ETC?

32 ATP (on average), 6 water

Mitochondria

-organelle that cellular respiration occurs in -has 2 membranes -the innermost space is called the matrix

ATP/ADP

-energy carrying rechargeable molecules that cells use to power processes -like a rechargeable battery

Pyruvic Acid the same as Pyruvate?

Yes

Lactic Acid

-acid that builds up in animal muscle cells during anaerobic respiration -bad for your cells; causes muscle cramps (one reason why anaerobic respiration isn't sustainable)

Aside from the CO2 produced during cellular respiration, what are other sources of CO2 in our atmosphere?

-burning fossil fuels -volcanic eruptions -fires/forrest fires -break down of organic matter (ex: decomposition of dead organisms)

Lactic Acid Fermentation Equation

Pyruvic Acid + NADH → Lactic Acid + NAD⁺

Alcoholic Fermentation Equation

pyruvic acid + NADH → alcohol + CO₂ + NAD⁺

What happens to cellular respiration rate during exercise?

-cellular respiration rate increases bc of higher demand for energy

Describe any difference btwn athletes and non-athletes respiration rate

-athlete is more conditioned so they have a higher rate of respiration

True / False: Cellular respiration occurs only in animals

False, it occurs in ALL organisms.

Where does the glucose come from that plants use for cellular respiration?

Photosynthesis

How are the processes of photosynthesis and cellular respiration dependent on one another?

-the reactants of one are the products of the other, vice versa

What happens to the CO2 that is produced during cellular respiration?

-it is exhaled out and released into the environment -a plant can use it for photosynthesis

What is the difference btwn a calorie and a Calorie?

-calorie: amount of energy needed to raise one gram of water by 1 degree Celsius -Calorie: 1,000 calories

How many Calories per gram of protein?

4 calories

How many Calories per gram of carbohydrate?

4 calories

How many Calories per gram of fat?

9 calories

How much ATP does fermentation produce?

2 ATP

Eye Piece

Contains the ocular lens

Nose Piece

Holds the high and low power objective lenses; can be rotated to change magnification

Objective Lenses

Magnification ranges from 4x to 40x

Stage Clips

Holds the slide in place

Stage

Supports the slide being viewed

Light Source

Projects light upwards through the diaphragm, the specimen, and the lenses

Arm

Used to hold the microscope when carried

Course Adjustment Knob

Moves the stage up and down for focusing (use this knob first)

Fine Adjustment Knob

Moves the stage slightly to sharpen the image (use second)

Diaphragm

Regulates the amount of light on the specimen

Base

supports the microscope

What is the most important biological process on the earth and why?

-Photosynthesis -Because if autotrophs were not able to make their own food then all other animals would not have food/no source of energy (plants are at the bottom of the food chain) -it also releases oxygen that we need into the environment

What does "photo" mean?

-"light"

What does "synthesis" mean?

-"to make"

Where does the Light Dependent Reactions (LDR) occur?

-in the thylakoid membrane

Where does the Light Independent Reactions (LIR)/Calvin Cycle occur?

-in the stroma

What is the equation for Photosynthesis? (Chemical Symbols)

6CO2 + 6H2O ------> C6H12O6 + 6O2

What is the equation for Photosynthesis? (in words)

carbon dioxide + water --(light)-> sugars + oxygen

Photosystems

-clusters of pigments that trap energy

How many photosystems are there? (That are used in photosynthesis)

2

Photon

-a particle representing a quantum of light or other electromagnetic radiation

A photon carries....

-energy

Summarize the LDR (Light Dependent Reactions)

-light strikes Photosystem II and excites the electrons (e-) -the electrons travel thru the ETC to Photosystem I -the energy from the electrons is used to pump Hydrogen ions across the membrane and creates a high concentration -water splits to replace the electrons that were at Photosystem II (photolysis) -the electron get re-excited at Photosystem I and bind with NADP+ to form NADPH -the high Hydrogen ion concentration powers ATP Synthase -ATP Synthase binds ADP with a P (phosphate) to form ATP

What replenishes the electrons that Photosystem II lost?

-when water splits, it gives Photosystem II (PII) electrons

Why does water split during LDR and what are the results?

-water spits to replenish PII with the electrons it lost -the Hydrogen ions go to the inside of the thylakoid to help create a high concentration -the Oxygen gas diffuses out through the stomata

Where is the stomata in leaves?

-the underside

When a photosystem gets hit with light energy.....

-the electrons leave

Inputs of LDR

-light energy, water (ADP + P, NADP+)

Outputs of LDR

-ATP, NADPH, O2

Why is the Calvin Cycle also called the Light Independent Reactions?

-because it does not directly use the energy from sunlight/it can run in the dark

What does the CalvinCycle Require?

-ATP and NADPH from the LDR

Summarize the Calvin Cycle/LIR

-Rubisco (an enzyme) transfers carbon from CO2 to RuBp (5 Carbons) -Now we have 3 sets of a 6 Carbon Molecule -It splits so now we have 6 sets of a 3 carbon molecule -ATP and NADPH is added so we have 6 sets of G3P -1 G3P leaves -the 5 G3P becomes 3 sets of 5 carbon molecule (RuBp); this is so the cycle is replenished -The Calvin Cycle happens twice per round of photosynthesis -the 2 sets of G3P bind together to form a glucose molecule

What is Carbon Fixation?

-it is the initial incorporation of CO2 into organic material -(the conversion of atmospheric carbon dioxide into organic molecules)

What is Rubisco?

-an enzyme that helps join CO2 with RuBp (5 carbon molecule)

What are the inputs of the Calvin Cycle/LIR?

-CO2, ATP, NADPH

What are the outputs of the Calvin Cycle/LIR?

-glucose

How many G3P make a glucose molecule?

2

What is the order of the Photosystems?

-photosystem II then photosystem I

How many CO2 molecules are used in one turn of the Calvin cycle?

three

How many turns of the Calvin Cycle happen per round of photosynthesis?

2

Electron Transport Chain (ETC)

series of electron carrier proteins that shuttle high-energy electrons during ATP-generating reactions

Heterotrophs

organisms that obtain food by consuming other living things

Autotrophs

organisms that make their own food

What is the structure of ATP?

-Adenine (nitrogenous base) -ribose (5- carbon sugar) -3 phosphate groups

How is ATP like a rechargeable battery/how does it store energy?

-by a controlled breaking and reforming of the chemical bonds btwn the atoms of the second and third phosphate group -when it is broken → energy is released -when it is formed/added → energy is stored

Pigments

light-absorbing molecules used by plants to gather the sun's energy

Thylakoids

-saclike photosynthetic membranes found in chloroplasts

Granum

-interconnected stacks of thylakoids

Stroma

-fluid portion of the chloroplasts; outside of the thylakoids