Lecture 6 easy

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Questions and Answers

What is the primary function of mitochondria in a cell?

Production of ATP (correct)

Photosynthesis

Protein synthesis

Energy storage

What feature of the inner membrane of mitochondria contributes to ATP production?

It contains cristae that increase surface area. (correct)

It is impermeable to all substances.

It is completely smooth.

It is thicker than the outer membrane.

Which of the following statements is true regarding the structure of mitochondria?

The outer membrane contains cristae.

The outer membrane is impermeable.

The inner membrane has a matrix containing enzymes. (correct)

Mitochondria have only one membrane.

Why do mitochondria have their own DNA and ribosomes?

To aid in protein synthesis and replication. Signup and view all the answers

How does the cristae of mitochondria enhance ATP production?

By providing a larger surface area for reactions. Signup and view all the answers

What are the two primary membranes of mitochondria?

The outer and inner membranes. Signup and view all the answers

What occurs when ATP molecules are broken down?

Energy is released for cellular processes. Signup and view all the answers

What is the primary function of mitochondria in eukaryotic cells?

To generate energy via oxidative phosphorylation Signup and view all the answers

What percentage of the outer membrane consists of lipids?

50% Signup and view all the answers

What type of proteins form channels in the outer membrane of mitochondria?

Porins Signup and view all the answers

What is the molecular weight limit for molecules passing through the outer membrane?

5,000-10,000 Da Signup and view all the answers

What is the role of ATP in eukaryotic cells?

To facilitate cellular movement and reproduction Signup and view all the answers

Which component is NOT found in the outer membrane of mitochondria?

Ribosomes Signup and view all the answers

Which of the following best describes the outer membrane of mitochondria?

Smooth and made up of equal parts lipids and proteins Signup and view all the answers

What process allows cells to convert energy stored in chemical bonds into usable ATP?

Oxidative phosphorylation Signup and view all the answers

What are the long folds of the inner membrane called?

Cristae Signup and view all the answers

What factors influence the conductivities of the mitochondrial membranes?

Chemical composition and structure Signup and view all the answers

What is the main characteristic of the lipid bilayer of the inner membrane?

Contains unusual phospholipids and is highly impermeable to ions Signup and view all the answers

What is the role of integral proteins in the inner membrane?

To make the inner membrane selectively permeable Signup and view all the answers

What is the structure of the cristae in most mitochondria?

Shelflike Signup and view all the answers

Where is the mitochondrial ATP synthase activity primarily located?

Inner membrane subunits Signup and view all the answers

What defines the intermembrane space in mitochondria?

It is located between the inner and outer membranes. Signup and view all the answers

What does the intercristal space contain?

Mitochondrial matrix Signup and view all the answers

Which components are intercalated in the inner membrane of mitochondria?

Compounds of the electron transport system Signup and view all the answers

What is the primary function of the cristae in mitochondria?

Increase surface area for biochemical reactions Signup and view all the answers

What is one of the main functions of the enzymes found in the mitochondrial matrix?

Citric acid cycle Signup and view all the answers

Which component of the mitochondrion encloses the matrix?

Inner membrane Signup and view all the answers

What is the primary function of sap vacuoles in plant cells?

Storing water and minerals Signup and view all the answers

What is a symptom commonly associated with mitochondrial diseases?

Poor muscle control Signup and view all the answers

What types of changes can lead to mitochondrial diseases?

Inherited or spontaneous mutations Signup and view all the answers

Which type of vacuole is most commonly found in fat cells?

Large central vacuoles Signup and view all the answers

What is the membrane surrounding a vacuole called?

Tonoplast Signup and view all the answers

Mitochondrial ribosomes are similar to those of which type of organism?

Bacteria Signup and view all the answers

What is the fluid present inside the vacuole referred to as?

Tonoplasm Signup and view all the answers

What is contained within the mitochondrial matrix?

Circular DNA Signup and view all the answers

What structure is formed by the folds of the inner membrane of the mitochondrion?

Cristae Signup and view all the answers

How are vacuoles typically formed?

From the ends of the cisternae of the Golgi apparatus Signup and view all the answers

Which pigment do sap vacuoles store in plants?

Anthocyanin Signup and view all the answers

Which of the following is NOT a potential outcome of mitochondrial diseases?

Improved metabolism Signup and view all the answers

What is the purpose of matrix granules in the mitochondrial matrix?

Regulation of calcium ion concentration Signup and view all the answers

What role do sap vacuoles play in maintaining plant cell structure?

Maintaining turgidity Signup and view all the answers

Which outer part of the mitochondrion separates it from the cytoplasm?

Outer membrane Signup and view all the answers

What type of vacuole is responsible for expelling excess water in certain protozoa?

Contractile vacuoles Signup and view all the answers

Which of the following is NOT a type of vacuole mentioned?

Production vacuoles Signup and view all the answers

What materials do vacuoles generally contain?

Water, minerals, and food Signup and view all the answers

Study Notes

Mitochondria Overview

Mitochondria are double-membrane organelles known as the "powerhouse of the cell."
They produce ATP (adenosine triphosphate), the usable form of energy for cells.
Enzymes convert energy from carbohydrates and fatty acids into ATP through oxidative phosphorylation.

Structure of Mitochondria

Composed of an outer and inner membrane.
The outer membrane is smooth and porous, allowing small molecules to pass.
The inner membrane is highly folded into cristae, increasing surface area for ATP production.
Contains a matrix rich in enzymes necessary for ATP synthesis and has its own DNA and ribosomes, enabling protein synthesis.

Function of Mitochondria

ATP produced is vital for cellular functions such as movement, reproduction, and synthesis of compounds.
Plays a crucial role in the oxidation of organic molecules to generate energy.

Outer Membrane Characteristics

Composed of 50% lipids and 50% proteins.
Contains transmembrane proteins called porins that form channels for small molecules.
Allows the passage of molecules with molecular weights up to 10,000 Da.

Inner Membrane Characteristics

Contains long folds (cristae) to enhance surface area.
Lipid composition varies and includes unusual phospholipids.
Highly impermeable to ions and selectively permeable to required small molecules.
Houses components of the electron transport chain and ATP synthase activity.

Membrane-Limited Spaces

Creates intermembrane space between the inner and outer membranes.
The matrix space is enclosed by the inner membrane and contains the mitochondrial matrix.

Mitochondrial Matrix

Composed of water, solutes, and matrix granules for calcium ion concentration regulation.
Contains circular DNA and ribosomes.
Enzymes in the matrix are involved in critical processes including the citric acid cycle and lipid oxidation.

Mitochondrial Diseases

Include over 40 conditions linked to mitochondrial dysfunction, due to mutations in nuclear or mitochondrial DNA.
Symptoms vary based on affected tissues, including muscle weakness, digestive problems, and developmental delays.

Vacuoles Overview

Non-cytoplasmic areas in cells, separated by a membrane known as tonoplast.
Store water, minerals, and other substances; vital for structure and osmotic pressure.

Types of Vacuoles

Sap Vacuoles: Abundant in plant cells for storing sap, maintaining turgidity, and osmotic pressure.
Contractile Vacuoles: Expandable and collapsible; help segregate substances and maintain osmotic balance.
Food Vacuoles: Store nutrients and participate in digestion via phagocytosis.
Air Vacuoles: Found in prokaryotes; store gases for buoyancy and structural strength.

Functions of Chloroplasts

Key roles in photosynthesis and synthesis of nucleic acids, proteins, fatty acids, and vitamins.

Peroxisomes

Single-membrane spherical organelles involved in hydrogen peroxide metabolism.
Contain oxidases that produce hydrogen peroxide and catalases that break it down.
Enzymes in peroxisomes assist in various metabolic reactions, including lipid degradation.

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Description

This quiz covers the structure and function of mitochondria, often referred to as the powerhouse of the cell. You'll learn about the double membrane structure, the role of ATP, and how cells harness energy from nutrients. Test your knowledge of these essential organelles.