Energy and Enzymes Chapter 4 Biology exam 3 🧪 (copy)

Energy

The capacity to do work.

Kinetic Energy

Energy of motion; energy that is present during work.

Potential Energy

Stored energy that has the potential to do work but is not currently in use.

How is energy stored biologically?

In food, as energy stored in chemical bonds.

Calories

Unit of measurement for energy.

Free Energy

Usable energy that can do work.

ATP

Adenosine triphosphate; the energy currency of cells.

Exergonic Reaction

Reactions that release energy; reactants possess more energy than products.

Endergonic Reaction

Reactions that require the input of energy; reactants possess less energy than products.

Catabolism

The process in which larger molecules are broken down into smaller molecules, releasing energy.

Anabolism

The process in which small molecules bond to form larger molecules, requiring energy input.

Enzymes

Biological catalysts that accelerate chemical reactions without being consumed.

Activation Energy

The amount of input energy required to start a reaction.

Optimal Enzyme Activity

Occurs at specific temperature ranges and pH for each enzyme.

Photosynthesis

The process by which plants convert light energy into chemical energy (sugar).

Light-dependent Reactions

Reactions that convert light energy into ATP and NADPH while splitting water.

Rubisco

The enzyme that binds CO2 in the Calvin cycle; the most abundant enzyme on the planet.

C3 Plants

Plants that use the standard Calvin cycle for photosynthesis, susceptible to oxygen interference.

C4 Plants

Plants that have an additional carbon fixation step to more efficiently utilize CO2.

Glycolysis

The metabolic pathway that converts glucose into pyruvate, yielding a small amount of ATP.

Transition Reaction

Converts pyruvate into acetyl-CoA before entering the Krebs cycle.

Krebs Cycle

The cycle that processes acetyl-CoA to produce NADH, FADH2, and ATP, occurring in mitochondria.

Electron Transport Chain

A process that transfers electrons through proteins embedded in the mitochondrial membrane to produce ATP.

Fermentation

An anaerobic process that occurs in the cytosol after glycolysis when oxygen is not available.

Lactic Acid Fermentation

A process where pyruvate is converted into lactic acid, occurring in muscles during rapid energy use.

Alcoholic Fermentation

A process where pyruvate is converted into ethanol and CO2, commonly occurring in yeast.

Metabolism

The sum of all chemical reactions within a cell.

Chemical Bonds

Connections between atoms that store energy and require energy to form.

Endergonic versus Exergonic

Endergonic reactions require energy input while exergonic reactions release energy.

NAD+

A coenzyme derived from Vitamin B3 that serves as an electron carrier in cellular respiration.

FAD+

A coenzyme derived from Vitamin B2 that functions similarly to NAD+ in cellular respiration.

ATP Synthase

An enzyme that uses H+ flow to synthesize ATP from ADP and inorganic phosphate.

Chlorophyll

The main pigment in plants that absorbs light energy for photosynthesis.

Adenosine Triphosphate (ATP)

A high-energy molecule that stores and supplies energy for cellular processes.

Chemical Reactions

Processes that involve the breaking and forming of bonds and require energy input.

Photosynthesis Stages

Light-dependent and light-independent (Calvin Cycle) reactions where light energy is transformed into chemical energy.

Photosynthesis Equation

6CO2 + 6H2O + light energy → C6H12O6 + 6O2.

Importance of Water in Photosynthesis

It acts as a source of electrons and is necessary for maintaining plant hydration.

Factors Affecting Enzyme Activity

Includes temperature and pH, which can alter enzyme shape and efficiency.

Anaerobic Respiration

When oxygen is not present, cells can still produce energy through fermentation.

Energy for Cellular Functions

ATP is required for growth, maintenance, reproduction, and other cellular activities.

Heterotrophs

Organisms that obtain energy through consuming other living things.

Autotrophs

Organisms that produce their own food through photosynthesis or chemosynthesis.

Aerobic Cellular Respiration

Process by which cells convert glucose and oxygen into energy, carbon dioxide, and water.

Thylakoid Membranes

Location in chloroplasts where light-dependent reactions occur.

Stroma

The fluid filled space surrounding the thylakoids in chloroplasts where the Calvin cycle occurs.

Glucose Catabolism

The breakdown of glucose to release energy for cellular functions.

Fermentation by-products

Lactic acid in animals and ethanol and CO2 in yeast.

Calvin Cycle

The light-independent reactions that fix carbon dioxide into organic compounds, primarily for glucose production.

Energy Acquisition from Food

The process of converting food into usable energy, primarily through ATP.

Thermodynamics in Metabolism

Study of energy transfer in chemical reactions during metabolism.

NADH and FADH2 Role

Molecules that carry high-energy electrons to the electron transport chain.

Cyclic Photophosphorylation

A process in light-dependent reactions that generates ATP without producing NADPH.

Non-Cyclic Photophosphorylation

A process that produces both ATP and NADPH during light-dependent reactions.

Metabolic Pathway

A series of enzymatic reactions that convert a substrate into a product.

Sources of Energy for Cellular Respiration

Primarily carbohydrates (glucose), fats, and rarely proteins.

Energy Investment Phase

Initial stages of glycolysis that use ATP to activate glucose for breakdown.

Energy Payoff Phase

Later stages of glycolysis that produce ATP and NADH.

Chain of Electron Transport

Sequential transfer of electrons through respiratory enzymes to build a proton gradient.

ATP Yield from Glucose

Total of 36-38 ATP molecules can be generated from one molecule of glucose.

Energy Needs of Animals

Energy from food is necessary for various biological functions, including muscle contraction and metabolism.

Plant Adaptations to Photosynthesis

Different mechanisms like C4 and CAM photosynthesis to survive environmental stress.

Environmental Effects on Photosynthesis

Factors like temperature and water availability can significantly impact photosynthesis efficiency.

Importance of Fermentation in Food Production

Essential for making products like bread, beer, and yogurt through anaerobic processes.

Cellular Respiration Overview

The process by which cells convert glucose into ATP in the presence of oxygen.

ATP's Role in Cellular Processes

ATP provides energy necessary for cellular activities such as synthesis and active transport.

Plant Growth Requirements

Plants need light, water, CO2, and nutrients for growth and photosynthesis.

Importance of RuBisCO

Key enzyme in the Calvin cycle for carbon fixation, facilitating sugar production from CO2.

Chloroplast Structure

Organelles where photosynthesis occurs, containing thylakoids and stroma.

Comparison of C3 and C4 Plants

C4 plants are more efficient under stress due to their specialized enzyme; C3 are not.

Chemical Bonds Energy Dynamics

Energy is stored in bonds; breaking them releases energy for use in cellular processes.

Efficiency of Glycolysis

Glycolysis is an energy-producing pathway that functions without oxygen.

Key Products of Glycolysis

Two 3C pyruvate, 2 ATP, and NADH as key outcomes of the glycolytic pathway.

Fermentation's Role in Energy Production

Converts energy anaerobically to sustain ATP production when oxygen is lacking.

Thylakoid Membrane Function

Site of light-dependent reactions transforming light energy into chemical energy.

Sugar Formation in Plants

Produced during the Calvin cycle and used as energy or for structural components.

Role of Electron Carriers

Coenzymes that transport electrons and hydrogens to mitochondria for respiration.

Hydration's Role in Photosynthesis

Water is necessary for electron supply and maintaining plant health.