Cellular Respiration Overview

Cellular Respiration

• Cellular respiration is the controlled release of energy from organic compounds in cells to form ATP
• The process breaks down glucose (C₆H₁₂O₆) to release energy
• The process involves a series of chemical reactions in the mitochondria
• The overall chemical equation for cellular respiration is: C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + 36 ATP (energy)
• The process includes stages like glycolysis, preparatory reaction, Krebs cycle, electron transport chain.

Focus Question

• The focus question is how the body gets energy from eating lettuce

Learning Objectives

• Explain the process of cellular respiration, including its stages, the role of oxygen
• Compare cellular respiration to photosynthesis
• Use models and diagrams to visualize energy flow and chemical equations

New Vocabulary

• Anaerobic process: a process that doesn't require oxygen
• Aerobic process: a process that requires oxygen
• Glycolysis: the first stage of cellular respiration
• Krebs cycle: a series of chemical reactions in the mitochondria
• Fermentation: an anaerobic process; a type of respiration

Review Vocabulary

• Cyanobacterium: a type of photosynthetic bacteria

Let's Meditate!

• The questions posed are about breathing, aerobic, and anaerobic respiration

Breathing

• Breathing supplies oxygen needed for cellular respiration and releases energy.
• The air we inhale has more oxygen and less carbon dioxide than the air we exhale.

Think

• Breathing is important to keep life going
• Inhaled air is different from exhaled air due to the exchange of oxygen and carbon dioxide.

Making energy in cells

• The process of breaking glucose and oxygen to create energy in cells
• Chemical reaction converting glucose and oxygen to carbon dioxide and water, releasing energy as ATP

Cell Respiration

• The controlled release of energy from organic compounds within cells to produce ATP.

Cellular Respiration

• The process of breaking down glucose (C₆H₁₂O₆) to make ATP, a form of chemical energy.

BioTheme: Interdependence

• Photosynthesis: 6 H₂O + 6 CO₂ + energy (sun) → C₁₂H₁₂O₆ + 6 O₂
• Cellular respiration: C₁₂H₁₂O₆ + 6 O₂ → 6 H₂O + 6 CO₂ + energy (ATP)

The Big Question

• Do animals and plants both respire?

Significant ATP Production

• Aerobic cellular respiration releases energy slowly by using oxygen to convert glucose into 36 ATP.

What is Cellular Respiration?

• Cellular respiration is a series of chemical reactions within mitochondria, where glucose is broken down to produce carbon dioxide, water, and ATP.
• C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + 38 ATP.

Plants vs Animals

• Plants use photosynthesis to make food, while animals eat other organisms.
• Both use cellular respiration to break down molecules to produce ATP.

What's the point?

• The point of cellular respiration is to make ATP.

Glycolysis

• Glycolysis occurs in the cytoplasm
• Glycolysis does not need oxygen
• Glucose breaks down into two three-carbon molecules, which creates 2 ATP molecule
• The next step in cellular respiration is required with the products of glycolysis in the mitochondria

Where is this ATP produced in a cell?

• Mitochondria

Function of Cellular Respiration

• Cellular respiration breaks down sugars to produce ATP for cellular activities

Location of Cellular Respiration

• Eukaryotes: Inside the mitochondria
• Prokaryotes: In the cytoplasm

Difference between prokaryotic and eukaryotic cells

• Prokaryotic cells lack a nucleus and membrane-bound organelles
• Eukaryotes have a nucleus and membrane-bound organelles, including mitochondria

Photosynthesis and Cellular Respiration

• Photosynthesis and cellular respiration are related, but not exact opposites.
• Cellular respiration uses oxygen to break down sugars and release energy.
• The chemical equation of cellular respiration is basically the reverse of photosynthesis. -Chloroplasts and mitochondria have similar structures.
• Mitochondria has two parts involved in cellular respiration: matrix and inner mitochondrial membrane, the processes happen in two stages: Krebs cycle and electron transport

Parts of Mitochondria

• Outer membrane
• Inner membrane
• Cristae
• Matrix

Processes in Mitochondria

• Stages of cellular respiration: Krebs cycle, electron transport.

What are the parts of a mitochondrion?

• Outer membrane
• Inner membrane
• Inner membrane space
• Cristae
• Matrix (innermost space)

Mitochondria

• Double-membrane-bound organelle. Inner membrane encloses fluid-filled matrix, folded cristae project into matrix increasing surface area
• Contains small circular DNA

Overview of Cellular Respiration

• Cellular respiration happens in stages (glycolysis, preparatory reaction, Krebs cycle, electron transport).
• It occurs in the mitochondria
• Glycolysis is anaerobic
• Aerobic respiration involves Krebs cycle and electron transport

Cellular Respiration: Aerobic and Anaerobic

• Aerobic respiration requires oxygen and is more efficient
• Anaerobic respiration does not require oxygen and is less efficient, shorter-term only.

Cellular Respiration Overview

• Cellular respiration: glucose + oxygen = carbon dioxide + water + ATP
• The primary purpose is to create ATP
• Two main ways to break down food: anaerobic (fermentation), and aerobic (cellular respiration glycolysis)

ATP-ADP Cycle

• ATP is converted to ADP to release energy
• ADP is converted back to ATP to store energy

Steps of Cellular Respiration

• Step 1: Glycolysis (in cytoplasm): glucose broken down to pyruvate, 2 ATP formed, 2 NADH produced.
• Step 2: Preparatory Reaction (in mitochondrial matrix): pyruvate converted to acetyl CoA, 2 NAD+ converted to 2 NADH, 2 CO₂ released.
• Step 3: Krebs Cycle (in mitochondrial matrix): acetyl CoA cycles to release CO₂, 2 ATP produced, 6 NAD+ converted to 6 NADH, 2 FAD+ converted to 2 FADH₂
• Step 4: Electron Transport Chain (in inner mitochondrial membrane): Electrons from NADH and FADH₂ move along electron transport chain, producing a proton gradient. Water is produced

Glycolysis

• Glucose is broken down in the cytoplasm through glycolysis.
• Two molecules of ATP and two molecules of NADH form from each broken down glucose molecule.

Krebs Cycle

• Acetyl CoA combines with a 4-carbon compound to form citric acid.
• Citric acid is broken down, releasing two molecules of carbon dioxide, generating one ATP, 3 NADH, and 1 FADH₂
• The cycle continues.

Krebs Cycle Net Yield

• The Krebs cycle produces 6 CO₂, 2 ATP, 8 NADH and 2 FADH₂.

Think: Glycolysis

• Two ATP molecules (net) and two NADH molecules are produced when glucose is broken down through glycolysis

Summary: Glycolysis

• Glycolysis starts with glucose, producing 4 ATP but uses 2 to split it, for a netto gain of 2 ATP.

Think: Krebs Cycle Location

• The Krebs cycle takes place in the mitochondrial matrix.

Think: Pyruvate Membranes

• A pyruvate molecule crosses two membranes of the mitochondria.

Electron Transport

• Electron transport occurs along the mitochondrial matrix
• Electrons are transferred and pass through three protein pumps, creating a hydrogen ion gradient
• The H⁺ ions then flow through ATP synthase, producing ATP from ADP and phosphate, this process occurs along the inner mitochondrial membrane

ATP Production During Cellular Respiration

• A table showing the ATP, NADH and FADH₂ production during each stage of cellular respiration.

This quiz explores cellular respiration, focusing on the breakdown of glucose to produce ATP and the chemical reactions involved. Learn about key stages such as glycolysis, the Krebs cycle, and the role of oxygen, while comparing cellular respiration to photosynthesis. Dive into the details of how energy is derived from food sources like lettuce.