Cell Structure: Mitochondria Overview
48 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the primary function of F1 particles in mitochondria?

  • Lipid storage
  • ATP production (correct)
  • Protein synthesis
  • DNA replication

What is the shape variation of mitochondria indicative of?

  • The genetic makeup of the organism
  • The age of the cell
  • The metabolic activity of the cell type (correct)
  • The nutrient availability in the environment

Which of the following components is NOT part of the mitochondrial structure?

  • Outer membrane
  • Mitochondrial matrix
  • Inner membrane
  • Nuclear membrane (correct)

What is the significance of extrachromosomal DNA in mitochondria?

<p>It plays a role in mitochondrial replication. (C)</p> Signup and view all the answers

How are mitochondria's sizes and numbers characterized within cells?

<p>Varies greatly depending on the cell's energy needs (D)</p> Signup and view all the answers

Which theory explains the origins of mitochondria?

<p>Serial symbiotic theory (D)</p> Signup and view all the answers

In which types of cells are mitochondria found?

<p>All eukaryotic cells (D)</p> Signup and view all the answers

What characteristic of living mitochondria differentiates them from static structures?

<p>Their movement within the cytoplasm (D)</p> Signup and view all the answers

What is the primary function of the cristae in mitochondria?

<p>Provide a large surface area for chemical reactions (D)</p> Signup and view all the answers

Which component of mitochondria directly relates to ATP production?

<p>Cristae (B)</p> Signup and view all the answers

What is found within the mitochondrial matrix?

<p>Mitochondrial ribosomes and DNA (A)</p> Signup and view all the answers

What effect does the number of cristae have on a cell's activity?

<p>More cristae correlates with higher activity levels (D)</p> Signup and view all the answers

Which of the following accurately describes the Citric Acid Cycle?

<p>It uses enzymes in the mitochondrial matrix to produce ATP (D)</p> Signup and view all the answers

The process of converting ADP into ATP primarily requires which of the following?

<p>Oxygen (D)</p> Signup and view all the answers

What is the shape of the cristae typically described as?

<p>Tubular or variably shaped (B)</p> Signup and view all the answers

How many circular DNA molecules can be found in the mitochondrial matrix?

<p>5 to 10 (B)</p> Signup and view all the answers

What is the main purpose of the Krebs/Citric acid cycle in aerobic respiration?

<p>To produce NADH for the electron transport chain (D)</p> Signup and view all the answers

Where does glycolysis take place within the cell?

<p>In the cytoplasm (A)</p> Signup and view all the answers

What is the role of NADH in aerobic respiration?

<p>To donate electrons and hydrogen ions to the electron transport chain (A)</p> Signup and view all the answers

Which two components make up oxidative phosphorylation?

<p>Electron transport chain and chemiosmosis (C)</p> Signup and view all the answers

What is the function of the ATP synthase F1 portion?

<p>To convert ADP and Pi into ATP (C)</p> Signup and view all the answers

What is created during chemiosmosis in mitochondria?

<p>An electrochemical gradient (B)</p> Signup and view all the answers

What do the F1FO particles in the mitochondrial inner membrane do?

<p>Synthesize ATP (A)</p> Signup and view all the answers

What is the significance of the electrochemical gradient in aerobic respiration?

<p>It drives the production of ATP (D)</p> Signup and view all the answers

What is the primary function of ATP synthase in the electron transport chain?

<p>To convert ADP and inorganic phosphate into ATP (D)</p> Signup and view all the answers

Which complexes in the electron transport chain are involved in proton pumping?

<p>Complex I, Complex III, and Complex IV (B)</p> Signup and view all the answers

What triggers the flow of protons through ATP synthase?

<p>The establishment of a proton gradient across the inner membrane (A)</p> Signup and view all the answers

From which cycle do the electrons that enter the electron transport chain primarily originate?

<p>Krebs cycle (C)</p> Signup and view all the answers

How do new mitochondria typically arise in a cell?

<p>By dividing equally during cell division (D)</p> Signup and view all the answers

What is the role of Complex IV in the electron transport chain?

<p>To reduce molecular oxygen to water (C)</p> Signup and view all the answers

What happens to protons during the process of electron transport?

<p>They are pumped from the matrix into the intermembrane space (A)</p> Signup and view all the answers

What happens to the concentration of protons when they are pumped into the intermembrane space?

<p>It creates a proton gradient across the inner mitochondrial membrane (C)</p> Signup and view all the answers

How do mitochondria replicate?

<p>Through binary fission similar to bacterial cell division (D)</p> Signup and view all the answers

What is the Serial Endosymbiotic Theory (SET) primarily concerned with?

<p>The evolution of mitochondria from prokaryotic symbionts (A)</p> Signup and view all the answers

Which type of cells are believed to have taken up aerobic bacteria according to the Serial Endosymbiotic Theory?

<p>Anaerobic cells that eventually became eukaryotes (A)</p> Signup and view all the answers

What significant cellular feature is formed from invaginations of the plasma membrane?

<p>Endoplasmic reticulum and nuclear envelope (C)</p> Signup and view all the answers

What is a key characteristic of the bacteria that became mitochondria?

<p>They have a prokaryotic origin and are aerobic (B)</p> Signup and view all the answers

Which cellular structures are believed to have evolved from photosynthetic bacteria?

<p>Chloroplasts (B)</p> Signup and view all the answers

According to the Serial Endosymbiotic Theory, what role did symbionts play in the evolution of eukaryotic cells?

<p>They served as energy sources for anaerobic cells (B)</p> Signup and view all the answers

What process is similar in mitochondria and bacteria?

<p>Fission (D)</p> Signup and view all the answers

What type of DNA do mitochondria and chloroplasts possess?

<p>Circular DNA (A)</p> Signup and view all the answers

Which of the following is true about the ribosomes of mitochondria and chloroplasts?

<p>They resemble bacterial ribosomes. (C)</p> Signup and view all the answers

Which process do mitochondria and chloroplasts share in common?

<p>They can replicate independently. (B)</p> Signup and view all the answers

What is the role of the 13 genes found in mtDNA?

<p>They provide instructions for making enzymes in oxidative phosphorylation. (D)</p> Signup and view all the answers

How do antibiotics affect mitochondria and chloroplasts?

<p>They can poison mitochondria and chloroplasts. (B)</p> Signup and view all the answers

Which of the following statements about eukaryotic cells is true?

<p>They may include animals, fungi, and plants. (A)</p> Signup and view all the answers

What distinguishes the origin of mitochondria and chloroplasts according to the Serial Endosymbiotic Theory?

<p>They descended from aerobic and photosynthetic bacteria. (D)</p> Signup and view all the answers

What is a significant feature of the invaginations of the plasma membrane related to the formation of the endoplasmic reticulum?

<p>They are not linked to the origin of mitochondria and chloroplasts. (A)</p> Signup and view all the answers

Flashcards

Mitochondria: What are they?

Mitochondria are organelles found in all eukaryotic cells, responsible for energy production through cellular respiration.

How are mitochondria visualized?

Mitochondria are visible with a light microscope, but their detailed structure requires an electron microscope.

Are mitochondria static?

Mitochondria are dynamic organelles that can change their shape and location within the cell, often congregating in areas of high energy demand.

What are the structural components of mitochondria?

Mitochondria have two membranes: an outer membrane which is smooth and a convoluted inner membrane that forms folds called cristae.

Signup and view all the flashcards

What are the compartments within a mitochondrion?

The space between the outer and inner membrane is called the intermembrane space, while the space enclosed by the inner membrane is called the mitochondrial matrix.

Signup and view all the flashcards

What is the significance of the inner membrane folds (cristae)?

The cristae of the inner mitochondrial membrane increase the surface area available for the electron transport chain, which is crucial for ATP production.

Signup and view all the flashcards

What does mtDNA do?

Mitochondrial DNA (mtDNA) is a small circular molecule located in the mitochondrial matrix, carrying the genetic code for some mitochondrial proteins.

Signup and view all the flashcards

What is the endosymbiotic theory?

The endosymbiotic theory proposes that mitochondria originated as free-living bacteria that were engulfed by early eukaryotic cells, forming a symbiotic relationship.

Signup and view all the flashcards

Cristae

Inner membrane of the mitochondria, folded into thin plates called cristae.

Signup and view all the flashcards

Mitochondrial Matrix

The space enclosed by the inner membrane of the mitochondria, containing enzymes and DNA.

Signup and view all the flashcards

Mitochondrial DNA (mtDNA)

A small circular piece of DNA found within the mitochondrial matrix.

Signup and view all the flashcards

Kreb's Cycle / Citric Acid Cycle

A series of chemical reactions that occur in the mitochondrial matrix, converting food energy into usable ATP.

Signup and view all the flashcards

Oxidative Phosphorylation

A process that uses oxygen to convert ADP to ATP, generating energy for the cell.

Signup and view all the flashcards

Adenosine Triphosphate (ATP)

The energy currency of the cell, used to power various cellular processes.

Signup and view all the flashcards

Cellular Respiration

The process that creates ATP using the energy from food.

Signup and view all the flashcards

Powerhouse of the Cell

Mitochondria's role in the cell.

Signup and view all the flashcards

Electron Transport Chain

The process of transferring electrons through a series of carriers in the mitochondrial membrane, releasing energy to pump protons.

Signup and view all the flashcards

NADH

The primary source of electrons for the electron transport chain, generated during the Krebs cycle.

Signup and view all the flashcards

ATP Synthesis

The process of converting ADP and inorganic phosphate (Pi) into ATP, using the energy from the proton gradient.

Signup and view all the flashcards

Electron Transport Complexes (I-IV)

Protein complexes embedded in the inner mitochondrial membrane that facilitate the transfer of electrons and pumping of protons.

Signup and view all the flashcards

How does the electron transport chain create a proton gradient?

The energy released during electron transport is used to pump protons (H+) from the mitochondrial matrix to the intermembrane space, creating a proton gradient.

Signup and view all the flashcards

ATP synthase

The flow of protons (H+) back across the inner mitochondrial membrane through ATP synthase, down their concentration gradient, powers the conversion of ADP and Pi to ATP.

Signup and view all the flashcards

Mitochondrial Reproduction

A process where mitochondria multiply within a cell to ensure sufficient energy production.

Signup and view all the flashcards

Endosymbiotic Theory of Mitochondrial Origin

Theory suggesting that mitochondria originated as free-living bacteria engulfed by early eukaryotic cells, establishing a symbiotic relationship.

Signup and view all the flashcards

Chemiosmosis

The process where the energy stored in the electron gradient is used to make ATP. It involves the movement of protons (hydrogen ions) across the mitochondrial membrane, through special channels, from the inner to the outer compartment.

Signup and view all the flashcards

Intermembrane Space

The space between the outer and inner membrane of the mitochondria, where protons accumulate during ATP production.

Signup and view all the flashcards

F1F0 Particles

Round particles protruding from the mitochondrial inner membrane that function as ATP synthase. The F1 part is the head and the F0 part is the base embedded in the membrane.

Signup and view all the flashcards

Mitochondria - origin

Mitochondria are believed to have originated from a symbiotic relationship between an ancestral eukaryotic cell and aerobic bacteria.

Signup and view all the flashcards

Serial Endosymbiotic Theory (SET)

The theory that explains how mitochondria became part of eukaryotic cells. It suggests a specific type of prokaryote, capable of aerobic respiration, was engulfed by a larger anaerobic cell, eventually leading to mitochondria.

Signup and view all the flashcards

How do mitochondria replicate?

The process by which mitochondria replicate, similar to asexual reproduction in bacteria. It involves a simple division into two daughter mitochondria.

Signup and view all the flashcards

Mitochondria's resemblance to bacteria

The structure of mitochondria resembles that of bacteria, with a double membrane similar to the cell wall of bacteria.

Signup and view all the flashcards

Mitochondria's role in cellular energy

Mitochondria are essential for cellular energy production.

Signup and view all the flashcards

Where are mitochondria found?

Mitochondria are found in virtually all eukaryotic cells, playing a crucial role in ATP production.

Signup and view all the flashcards

Evidence for the Theory (SET)

The endosymbiotic theory is backed by evidence, including similarities between mitochondria and bacteria in structure, DNA, and the process of replication.

Signup and view all the flashcards

What evidence suggests mitochondria and chloroplasts were once independent organisms?

Mitochondria and chloroplasts have their own circular DNA, similar to bacteria, which supports the theory that they were once independent organisms.

Signup and view all the flashcards

What ability do mitochondria and chloroplasts have that suggests their bacterial ancestry?

Mitochondria and chloroplasts can produce their own proteins, further indicating their bacterial origin.

Signup and view all the flashcards

How do mitochondria and chloroplasts replicate?

Mitochondria and chloroplasts can replicate independently within the cell, similar to bacteria.

Signup and view all the flashcards

What are the ribosomes inside mitochondria and chloroplasts like?

Mitochondria and chloroplasts have ribosomes more closely resembling those found in bacteria, further supporting their bacterial origin.

Signup and view all the flashcards

Why are antibiotics detrimental to mitochondria and chloroplasts?

Bacterial antibiotics, which target bacterial components, can poison mitochondria and chloroplasts, demonstrating their sensitivity to these drugs and reinforcing their bacterial ancestry.

Signup and view all the flashcards

What is the order of events in the Serial Endosymbiotic Theory?

The Serial Endosymbiotic Theory (SET) suggests that mitochondria evolved first, and then chloroplasts originated from the engulfment of photosynthetic bacteria by early eukaryotic cells.

Signup and view all the flashcards

Study Notes

Cell Structure: Mitochondria

  • Mitochondria are the second most prominent organelles within cells, visible with a light microscope but requiring an electron microscope for detailed structure.
  • They are found in all eukaryotic cells (plant and animal), with numbers varying from a few to over a thousand per cell.
  • The shape of mitochondria can vary from rods to spheres and they are characteristic of a particular cell type.
  • Mitochondria are not static and move around within the cytoplasm of cells, often aggregating in areas of high metabolic activity.
  • Mitochondria are 0.5-1.0 μm in diameter and 5-10 μm long.
  • Each mitochondrion is bound by two membranes: a smooth outer membrane and an inner membrane folded into cristae.

Mitochondrial Structure and Morphology

  • Mitochondria are composed of an outer membrane, an inner membrane, the intermembrane space and the matrix.
  • The cristae are infolds of the inner membrane which provide a large surface area for chemical reactions.
  • The number of cristae directly correlates with a cell’s activity level.
  • The matrix contains mitochondrial ribosomes, non-chromosomal DNA (in the form of 5-10 identical circular DNA molecules around 2-3nm in diameter), and enzymes for the Krebs/Citric acid cycle. The matrix converts chemical energy from food into ATP.

Mitochondrial Function

  • Mitochondria are called the "powerhouse of the cell" due to their role in ATP production via oxidative phosphorylation.
  • Oxidative phosphorylation uses oxygen to convert ADP into ATP, crucial for cellular metabolic processes.
  • The process involves the breakdown of glucose (during glycolysis and the Krebs cycle) and the transfer of electrons to produce NADH and FADH2. These molecules carry electrons and protons (hydrogens ions).
  • The electron transport chain (ETC) in the inner mitochondrial membrane uses the energy from the electrons to pump protons (H+) from the matrix to the intermembrane space.
  • The movement of protons back into the matrix through ATP synthase generates ATP.
  • The Krebs cycle (or citric acid cycle) is a central set of reactions that collectively produce ATP.

Mitochondrial Reproduction and Origin

  • Mitochondria reproduce similarly to bacteria, a process called fission.
  • When a cell divides, mitochondria are split equally to daughter cells.
  • These new mitochondria arise from already existing mitochondria.
  • Mitochondria replicate independently through cell division
  • The serial endosymbiotic theory is a leading theory to explain mitochondrial origins. It proposes that mitochondria evolved from aerobic bacteria that were engulfed by another prokaryotic cell.
  • Supporting evidence for the endosymbiotic theory includes mitochondria having their own circular DNA (mtDNA), their own protein production machinery, and the ability to replicate independently.

ATP Synthase - F₁Fo Particles

  • The inner mitochondrial membrane is studded with F₁ particles projecting from the membrane, with a Fo base embedded in the membrane.
  • ATP synthase is an enzyme complex that catalyzes the synthesis of ATP from ADP and inorganic phosphate (Pi).
  • The energy for ATP synthesis comes from the flow of H⁺ ions through the enzyme.
  • The F₁ subunit squeezes ADP + Pi together to form ATP, then releases the ATP.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Related Documents

Funbio 6 2024 Cell Structure Mitochondria PDF

Description

Explore the essential structure and function of mitochondria, the powerhouse of the cell. Learn about their unique morphology, movement within the cytoplasm, and significance in eukaryotic cells. This quiz delves into critical aspects of mitochondrial biology essential for understanding cellular metabolism.

More Like This

Mitochondria Structure and Function Quiz
29 questions

Mitochondria Structure and Function Quiz

AstoundedConsciousness243 avatar
AstoundedConsciousness243
Mitochondrial Structure and Function
5 questions

Mitochondrial Structure and Function

SpotlessFarce avatar
SpotlessFarce
Mitochondrial Structure and Function
5 questions

Mitochondrial Structure and Function

SpotlessFarce avatar
SpotlessFarce
Mitochondria: Structure and Function
15 questions

Mitochondria: Structure and Function

WholesomeBanshee6602 avatar
WholesomeBanshee6602
Use Quizgecko on...
Browser
Open
Browser
Browser