Cellular Energy Acquisition and Metabolism Overview, Energy Generation in Mitochondria: Oxidative Phosphorylation, Intracellular Compartments and Protein Transport Overview

Metabolism

Biochemical reactions extracting energy from food.

Activation Energies

Energy required to initiate chemical reactions.

Cellular Respiration

Catabolic process breaking down organic material.

Electron Transport Chain

Series of protein complexes generating ATP.

Glycolysis

First stage of sugar breakdown into pyruvate.

Citric Acid Cycle

Cycle producing GTP, NADH, and FADH2.

Oxidative Phosphorylation

ATP generation via electron transport and chemiosmosis.

Substrate-Level Phosphorylation

Direct ATP production from metabolic reactions.

Acetyl-CoA

Key molecule linking glycolysis to citric acid cycle.

Glycogen

Stored form of glucose in animal cells.

Gluconeogenesis

Synthesis of glucose from non-carbohydrate sources.

Energy Charge

Measurement of ATP, ADP, and AMP levels.

Feedback Regulation

Mechanism allowing cells to switch metabolic pathways.

Glycogen Synthase

Enzyme promoting glycogen synthesis from glucose.

Glycogen Phosphorylase

Enzyme breaking down glycogen to glucose.

ATP Turnover

Rate at which ATP is consumed and regenerated.

Pyruvate

End product of glycolysis, precursor to acetyl-CoA.

NADH

Electron carrier generated in glycolysis and citric acid cycle.

FADH2

Electron carrier produced in the citric acid cycle.

Building Blocks

Components derived from macromolecule digestion for synthesis.

High-Energy Electrons

Electrons released during cellular respiration for ATP production.

Energy Yield

Amount of energy produced from metabolic processes.

Oxidative Phosphorylation

Uses food energy to produce ATP in mitochondria.

Photosynthesis

Converts sunlight energy into chemical energy in chloroplasts.

Proton Gradient

Difference in proton concentration across a membrane.

ATP Synthase

Enzyme that synthesizes ATP using proton gradient energy.

Chemiosmotic Coupling

Links ATP formation with proton gradient generation.

Citric Acid Cycle

Oxidizes acetyl-CoA to produce high-energy electrons.

Electron Transport Chain (ETC)

Series of complexes that transfer electrons and pump protons.

NADH

Electron carrier that donates electrons to the ETC.

FADH2

Another electron carrier with lower ATP production efficiency.

Proton Pumping

Process of moving protons to create a gradient.

Electrochemical Gradient

Combination of electrical and chemical gradients across a membrane.

Proton-Motive Force

Energy stored in the electrochemical gradient.

NADH Dehydrogenase Complex

First complex in ETC that accepts electrons from NADH.

Cytochrome C Reductase Complex

Second complex in ETC involved in electron transfer.

Cytochrome C Oxidase Complex

Final complex in ETC that reduces oxygen.

ATP Hydrolysis

Process of breaking down ATP to release energy.

Antiporter

Transport protein that moves substances in opposite directions.

ADP to ATP Conversion

Rapid process maintaining high ATP/ADP ratio in cells.

Cellular Respiration Efficiency

38-50% energy capture from glucose during respiration.

Redox Potential

Measure of an electron's affinity for reduction.

Ubiquinone

Electron shuttle that carries electrons and protons.

Cytochrome C

Electron carrier with a porphyrin ring and iron.

Oxygen-Binding Site

Site in cytochrome c oxidase that binds molecular oxygen.

Water Formation Reaction

4e- + 4H+ + O2 → 2H2O in ETC.

Mitochondrial Dynamics

Mitochondria change structure and location based on energy needs.

Proton Gradient Utilization

Gradient drives transport of pyruvate and phosphate.

Prokaryotic Cells

Single compartment cytoplasm without membrane-enclosed organelles.

Eukaryotic Cells

Multiple internal compartments with membrane-enclosed organelles.

Surface Area to Volume Ratio

Influences cell size and biochemical efficiency.

Nucleus

Contains genomic DNA and synthesizes ribosomes.

Endoplasmic Reticulum

Synthesis of proteins and lipids; detoxification.

Rough ER

Studded with ribosomes; synthesizes proteins for membranes.

Smooth ER

Synthesizes lipids and detoxifies harmful substances.

Golgi Apparatus

Modifies and distributes proteins and lipids from ER.

Lysosomes

Breaks down macromolecules and worn-out organelles.

Peroxisomes

Contains enzymes for lipid breakdown and detoxification.

Mitochondria

Powerhouse of the cell; site of ATP synthesis.

Chloroplasts

Site of photosynthesis in plant cells; contains thylakoids.

Endosomes

Involved in sorting and transporting endocytosed materials.

Cell Volume

Determined by the amount of cytoplasm and organelles.

Ion Gradients

Used for energy demands and biochemical processes.

Differentiation

Specialization of cells in multicellular organisms.

Membrane-enclosed Organelles

Structures that compartmentalize cellular functions.

Biochemical Processes

Chemical reactions essential for cell function.

Compartment Sorting

Transport of materials to/from organelles.

Endomembrane System

Includes ER, Golgi, lysosomes, and vesicles.

Vesicular Exchange

Communication between organelles and plasma membrane.

Cytosolic Ribosomes

Most proteins synthesized by ribosomes in cytosol.

Sorting Signal

Amino acid sequence directing protein destination.

Nuclear Pores

Gateways for molecules entering/exiting nucleus.

Protein Translocators

Membrane proteins facilitating protein transport.

Transport Vesicles

Carry proteins between endomembrane system organelles.

Signal Sequence

15-60 amino acids directing protein sorting.

Nuclear Envelope

Double membrane surrounding the nucleus.

Inner Nuclear Membrane

Anchors nuclear lamina and binds chromosomes.

Outer Nuclear Membrane

Continuous with endoplasmic reticulum membrane.

Nuclear Pore Complex

30 proteins forming selective gating structure.

Energy-Dependent Passage

Requires energy for nuclear pore transport.

Nuclear Localization Signal

Sequence binding import receptor for nuclear entry.

Ran-GTP

Molecule facilitating protein release in nucleus.

Mitochondrial Precursor Protein

Protein needing import receptor for mitochondrial entry.

Chaperone Proteins

Assist in refolding proteins after import.

Peroxisomes

Organelles digesting toxins and synthesizing phospholipids.

Signal Peptidase

Enzyme cleaving signal sequence in mitochondria.

Lipid-Carrying Proteins

Transport phospholipids to mitochondria and chloroplasts.

Cytosolic Proteins

Proteins that lack signal sequences for sorting.

Myelin Sheath

Insulating layer around nerve fibers, enhancing signal transmission.

Cytosol

Fluid component of the cytoplasm where proteins are synthesized.

Translocator Protein

Protein that facilitates cargo entry into peroxisomes.

Peroxisome

Organelle involved in lipid metabolism and detoxification.

Endoplasmic Reticulum (ER)

Extensive membrane system for protein and lipid synthesis.

Soluble Proteins

Proteins fully translocated into ER lumen for processing.

Integral-Membrane Proteins

Proteins partially embedded in ER membrane, involved in signaling.

Exocytosis

Process of vesicles fusing with plasma membrane to release contents.

Common Pool of Ribosomes

Ribosomes function freely or membrane-bound.

Translation

Process of synthesizing polypeptides from mRNA.

Soluble Proteins

Proteins synthesized in the ER and released into lumen.

Signal-Recognition Particle (SRP)

Binds ER signal sequence and ribosome, slowing translation.