Bio Exam 2 Review

Cellular Respiration

process of extracting energy from oxidizing glucose then storing it in ATP

Metabloism

sum of all chemical reations in organism that require energy

Exergonic

reactions that release energy

Endergonic

reactions that require energy

Enzymes

proteins that speed up chemical reactions

Enzyme Substrate Specificity

the selectivity of an enzyme, a enzyme can only bond to certain substrates.

Active Site

region on an enzyme where the substrate binds.

ATP

adenosine triphosphate / higher energy

ADP

adenosine diphosphate / less energy

Oxidation

when a molecule loses electrons

Reduction

when a molecule gains electrons

Redox Reactions

chemical reactions that transfer electrons between reactants

Electron Carriers

molecules that can carry high energy electrons through the electron transport chain

Electron Transport Chain

sequence of electron carrier molecules that transport electrons during the redox reactions that release energy used to make ATP

Primary Electron Carriers in Cellular Respiration

NAD+/NADH & FAD/FADH2

Glycolysis

breakdown of glucose into pyruvate

Glycolysis Location

occurs in the cytoplasm

Glycolysis Reaction

glucose + 2ATP + 2NAD+ = 2 pyruvate + 2NADH + 2ATP(net)

Pyruvate Oxidation

pyruvate are transported to the mitochondria so that energy can be harvested

Pyruvate Oxidation Location

mitochondrial matrix

Pyruvate Oxidation Reaction

2 pyruvate + 2 CoA + 2NAD+ = 2 Acetyl CoA + 2Co2 + 2 NADH

Chemiosmosis

the process where H⁺ ions flow back through ATP synthase, producing ATP

Total ATP yield from cellular respiration

~30-32 ATP per glucose molecule (varies by cell type)

Fermentation

an anaerobic process that regenerates NAD⁺ to keep glycolysis running

Two types of fermentation

lactic acid fermentation (e.g., muscle cells, yogurt) and alcohol fermentation (e.g., yeast, beer)

Inputs and outputs of Lactic acid fermentation

Pyruvate + NADH = Lactic acid + NAD⁺

Inputs and outputs of Alcohol fermentation

Pyruvate + NADH = Ethanol + CO₂ + NAD⁺

Role of oxygen in cellular respiration

final electron acceptor in the ETC, forming water

Happens if oxygen is not available in cellular respiration

cells switch to fermentation to regenerate NAD⁺, producing less ATP.

Role of enzymes in cellular respiration

regulate and speed up reactions (e.g., ATP synthase, Rubisco).

How cellular respiration regulated

feedback inhibition (e.g., high ATP levels inhibit enzymes, low ATP levels activate them).

Anaerobic Respiration

does not require oxygen and produces less ATP

Aerobic Respiration

requires oxygen & produces more ATP

Oxidative Phosphorylation location

inner mitochondrial membrane

Substrate Level Phosphorylation

the formation of ATP by directly transferring a phosphate group to ADP from an intermediate substrate in catabolism.

ATP Synthase

allows protons to move back into the matrix

ATP Synthase Location

inner mitochondrial membrane

Proton Motive Force

energy from proton gradient driving ATP synthesis

Energy production in Glycolysis

2 ATP & 2 NADH

Energy production in Pyruvate Oxidation

2 NADH

Energy production in Citric Acid Cycle

2 ATP, 6 NADH, 2 FADH

Energy Production in Oxidative Phosphorylation

~ 32 ATP

Aerobic Processes located in the Mitochondria

Pyruvate Oxidation, Citric Acid Cycle, & Oxidative Phosphorylation

Anaerobic Processes located in the Cyptoplasm

Glycolysis, & Fermentation

Photosynthesis

process where plants convert light energy, CO₂, and water into glucose and oxygen

Two main stages of Photosynthesis

1. Light-dependent reactions, 2. Calvin Cycle (light-independent reactions)

Light-dependent reactions Location

thylakoid membranes of chloroplasts

Inputs and Outputs of the light-dependent reactions

Light, H₂O, NADP⁺ & ADP = O₂, ATP, NADPH.

Calvin cycle location

stroma of chloroplasts.

Inputs and outputs of the Calvin Cycle

CO₂, ATP, & NADPH = G3P

G3P

molecule that is made in the Calvin cycle; glucose is formed when two of these molecules combine

Role of chlorophyll in photosynthesis

absorbs light energy, primarily in the blue and red wavelengths

Two photosystems involved in the light-dependent reactions

Photosystem II (PSII) and Photosystem I (PSI)

Role of water in photosynthesis

split to provide electrons and protons for the light-dependent reactions, releasing O₂ as a byproduct

Electron Transport Chain (ETC) in photosynthesis

series of proteins that transfer electrons, pumping H⁺ ions to create a proton gradient for ATP synthesis

Role of NADP⁺ in photosynthesis

reduced to NADPH, which carries electrons to the Calvin Cycle

Calvin Cycle's main goal

fix carbon dioxide into organic molecules (e.g., G3P) using ATP and NADPH

Enzyme Rubisco

attaches carbon to RuBP

How many turns of the Calvin Cycle are needed to produce one glucose molecule

6 turns (since each turn produces 1 G3P, and 2 G3P are needed to make glucose).

Relationship between photosynthesis and cellular respiration

are complementary processes: photosynthesis produces glucose and oxygen, which are used in cellular respiration, and vice versa.

Autotrophs

organisms that produce their own food (e.g., plants, algae, some bacteria).

Heterotrophs

organisms that consume organic molecules for energy (e.g., animals, fungi, humans).

Electromagnetic spectrum

range of all possible wavelengths of light, including visible light used in photosynthesis.

Why plants appear green

chlorophyll reflects green light and absorbs blue and red light

Accessory pigments

pigments like chlorophyll b and β-carotene that absorb light at different wavelengths and transfer energy to chlorophyll a

Difference between light-dependent and light-independent reactions

Light-dependent reactions require light and produce ATP and NADPH. Light-independent reactions don't require light directly, but use ATP and NADPH to fix CO₂.

Citric Acid Cycle Location

Mitochondrial Matrix

Citric Acid Cycle

breaks remaining covalent bonds in Acetyl CoA

Citric Acid Cycle Reaction

2 Acetyl CoA + 6 NAD + 2 FAD = Oxaloacetate + 4 CO2 + 2 ATP + 6 NADH + 2 FADH2