Cell Structure and Process Overview

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Questions and Answers

Which of the following is a characteristic of prokaryotic cells?

Presence of mitochondria

Presence of a membrane-bound nucleus

Single circular chromosome (correct)

Multiple linear chromosomes

Eukaryotic cells have membrane-bound organelles.

True

What are plasmids and where are they typically found?

Plasmids are small extra-chromosomal DNA molecules found in prokaryotes.

Eukaryotes have a __________ nucleus, while prokaryotes do not.

membrane-bound Signup and view all the answers

Match the type of cell with its characteristics:

Prokaryote = Single circular chromosome Eukaryote = Membrane-bound organelles Signup and view all the answers

Which of the following organelles are absent in prokaryotic cells?

All of the above Signup and view all the answers

What is the principal component of cell walls in plant cells?

Cellulose Signup and view all the answers

Both prokaryotic and eukaryotic cells contain plasmids.

False Signup and view all the answers

Chloroplasts are responsible for cellular respiration in plant cells.

False Signup and view all the answers

What is chitin made of?

A polymer of acetyl-glucosamine Signup and view all the answers

What is the main difference between fission and mitosis?

Fission is a method of asexual reproduction in prokaryotes, while mitosis is a process of cell division in eukaryotes. Signup and view all the answers

Bacterial cell walls are primarily made of __________.

peptidoglycans Signup and view all the answers

Match the following cell types with their corresponding cell wall components:

Plant cells = Cellulose Fungal cells = Chitin Bacterial cells = Peptidoglycans Animal cells = No cell wall Signup and view all the answers

Which structure is typically absent in prokaryotic cells that is present in eukaryotic cells?

Nucleus Signup and view all the answers

Prokaryotic cells always possess a cell wall.

True Signup and view all the answers

What are ribosomes primarily responsible for in prokaryotic cells?

Protein synthesis Signup and view all the answers

The cell wall of most bacteria is made of __________.

peptidoglycan Signup and view all the answers

Match the following structures with their functions in bacterial cells:

Pili = Cell adhesion and locomotion Flagellum = Movement Capsule = Protection and adherence Plasma membrane = Barrier and transport Signup and view all the answers

Which of the following organelles is absent in prokaryotic cells?

Mitochondria Signup and view all the answers

Animal cells possess cell walls.

False Signup and view all the answers

In what part of the prokaryotic cell is the chromosome located?

Cytoplasm Signup and view all the answers

Pili may be associated with __________ in pathogenic bacteria.

cell adhesion Signup and view all the answers

Which of the following statements accurately describes the composition of bacterial capsules?

Composed of polysaccharides Signup and view all the answers

What is a key difference between plant cells and animal cells regarding centrosomes?

Animal cells have centrosomes. Signup and view all the answers

Eukaryotic cells reproduce via mitosis.

True Signup and view all the answers

What organelle is responsible for photosynthesis in plant cells?

Chloroplast Signup and view all the answers

The __________ is the organelle where genetic information is stored in eukaryotic cells.

nucleus Signup and view all the answers

Match the following components to their respective cell types:

Chloroplast = Plant Cell Centrosome = Animal Cell Nucleus = Both Cell Wall = Plant Cell Signup and view all the answers

Which of the following structures are essential for locomotion in eukaryotic cells?

Microtubules Signup and view all the answers

Animal cells contain chloroplasts.

False Signup and view all the answers

Which type of RNA is synthesized in the nucleus from DNA?

Messenger RNA (mRNA) Signup and view all the answers

The nuclear envelope consists of __________ lipid bilayers.

two Signup and view all the answers

Which of the following is NOT present in plant cells?

Centrosome Signup and view all the answers

What is one of the primary functions of peroxisomes?

Breakdown of hydrogen peroxide Signup and view all the answers

Centrosomes are present in both plant and animal cells.

False Signup and view all the answers

What significant cycle occurs in germinating plant seeds?

glyoxylate cycle Signup and view all the answers

Peroxisomes are involved in the breakdown of fatty acids and amino acids, as well as a variety of ______.

toxins Signup and view all the answers

Match the following cellular structures with their functions:

Peroxisomes = Breakdown of hydrogen peroxide and fatty acids Centrosomes = Microtubule organizing centers Vacuoles = Storage of water and nutrients Glyoxylate cycle = Anabolic process in germinating seeds Signup and view all the answers

Why do vacuoles often get associated specifically with plants?

Plants have a large central vacuole. Signup and view all the answers

Both plant and animal cells can have vacuoles.

True Signup and view all the answers

What structure is composed of a pair of centrioles?

centrosome Signup and view all the answers

The central vacuole in plant cells helps maintain ______ pressure.

turgor Signup and view all the answers

At which pH are enzymes in peroxisomes optimally active?

pH 5 Signup and view all the answers

What is one of the primary functions of peroxisomes?

Breakdown of hydrogen peroxide Signup and view all the answers

Vacuoles are only found in plant cells.

False Signup and view all the answers

What cycle takes place in germinating seeds?

glyoxylate cycle Signup and view all the answers

The centrosome consists of a pair of __________.

centrioles Signup and view all the answers

Match the following organelle functions with their respective organelles:

Glyoxylate cycle = Production of larger carbohydrates in seeds Peroxisomes = Breakdown of fatty acids and toxins Centrosomes = Microtubule organizing centers Vacuoles = Storage of nutrients and water Signup and view all the answers

Which of the following statements about prokaryotic cells is true?

Prokaryotic cells have a circular chromosome not enclosed in a membrane. Signup and view all the answers

Animal cells typically possess cell walls.

False Signup and view all the answers

What is the primary component of the bacterial cell wall?

peptidoglycan Signup and view all the answers

Prokaryotic cells lack __________ nuclei, which differentiates them from eukaryotic cells.

membrane-bound Signup and view all the answers

Match the following structures found in bacterial cells with their respective functions:

Pili = Cell adhesion and movement Flagellum = Locomotion Capsule = Protection from the environment Cell wall = Structural support Signup and view all the answers

Which of the following organelles are typically found in prokaryotic cells?

Ribosomes Signup and view all the answers

All prokaryotic cells are unicellular organisms.

True Signup and view all the answers

In which part of a prokaryotic cell is the genetic material located?

cytoplasm Signup and view all the answers

The __________ surrounding a bacterial cell wall is often composed of hydrated polysaccharides.

capsule Signup and view all the answers

Which of the following is NOT typically associated with prokaryotic cells?

Nucleus Signup and view all the answers

What is the primary function of ribosomes?

Protein synthesis Signup and view all the answers

The rough endoplasmic reticulum is called rough because it is smooth in appearance.

False Signup and view all the answers

What type of proteins do free ribosomes typically produce?

Cytoplasmic proteins Signup and view all the answers

The nucleolus is primarily involved in the synthesis of ______.

ribosomal RNA Signup and view all the answers

Which structure is associated with the synthesis of glycoproteins?

Rough endoplasmic reticulum Signup and view all the answers

Ribosomes are found only in eukaryotic cells.

False Signup and view all the answers

Where are proteins synthesized that are destined to be secreted outside the cell?

Rough endoplasmic reticulum Signup and view all the answers

Ribosomes catalyze the formation of ______ bonds between amino acids.

peptide Signup and view all the answers

Match the following organelles with their main functions:

Nucleolus = Ribosomal RNA synthesis Rough ER = Protein synthesis for secretion Smooth ER = Lipid synthesis Golgi apparatus = Protein modification and transport Signup and view all the answers

What distinguishes the rough endoplasmic reticulum from the smooth endoplasmic reticulum?

Presence of ribosomes Signup and view all the answers

What is the primary function of the smooth endoplasmic reticulum?

Synthesis of phospholipids and steroid hormones Signup and view all the answers

Mitochondria are responsible for making ATP in both prokaryotic and eukaryotic cells.

False Signup and view all the answers

What process occurs in the Golgi apparatus?

Modification and packaging of proteins and lipids Signup and view all the answers

The ______ cycle is also known as the Krebs cycle.

citric acid Signup and view all the answers

Match each structure with its function:

Rough ER = Protein synthesis and processing Smooth ER = Lipid synthesis and detoxification Golgi apparatus = Modification and distribution of proteins Mitochondria = ATP production Signup and view all the answers

Which of the following best describes a role of the liver in relation to smooth ER?

Breakdown of toxins Signup and view all the answers

Proteins synthesized in the rough ER are packaged directly into lysosomes.

False Signup and view all the answers

What is the primary energy currency of the cell?

ATP Signup and view all the answers

In eukaryotes, pyruvate is converted into _____ before entering the citric acid cycle.

acetyl-CoA Signup and view all the answers

What occurs to proteins destined for secretion after they leave the Golgi apparatus?

They are released outside the cell. Signup and view all the answers

What type of cells have a membrane-bound nucleus?

Eukaryotic cells Signup and view all the answers

Prokaryotes are known to have multiple linear chromosomes.

False Signup and view all the answers

What are the two major types of cells discussed?

Prokaryotes and eukaryotes Signup and view all the answers

Eukaryotic cells contain __________ for energy production, while prokaryotic cells lack this organelle.

mitochondria Signup and view all the answers

Match the cell type with its characteristic.

Prokaryotic = No membrane-bound organelles Eukaryotic = Contains mitochondria Signup and view all the answers

Which of the following features is unique to eukaryotic cells?

Chloroplasts (in plants) Signup and view all the answers

Plasmids are commonly found in eukaryotic cells.

False Signup and view all the answers

What is the function of telomeres in eukaryotic chromosomes?

To protect the ends of linear chromosomes Signup and view all the answers

Study Notes

Cell Types and Structure

Two major types of cells: prokaryotes and eukaryotes.
Prokaryotes include bacteria, characterized by the absence of a nucleus and membrane-bound organelles.
Eukaryotes include fungi, plant cells, and animal cells, featuring a membrane-bound nucleus and organelles such as mitochondria, chloroplasts, and Golgi apparatus.

Nucleus and Chromosome Structure

Prokaryotic cells have a single circular chromosome located in the cytoplasm, devoid of ends or telomeres.
Eukaryotic cells have multiple linear chromosomes within the nucleus, typically organized as 23 pairs in humans (46 total chromosomes).
Eukaryotic chromosomes end in telomeres unlike prokaryotic chromosomes.

Genetic Information and Reproduction

Prokaryotes reproduce via binary fission with no mitotic phases or microtubule organizing centers.
Eukaryotes undergo mitosis, involving complex processes such as prophase and metaphase, with centrosomes acting as microtubule organizing centers in animal cells.

Cell Wall Composition

Prokaryotic cell walls are primarily composed of peptidoglycan, whereas plant cell walls are made of cellulose and fungal cell walls are made of chitin.
Animal cells lack cell walls, making them more susceptible to osmotic lysis, unlike plant cells that maintain turgor pressure.

Bacterial Cell Structure

Bacterial cells possess ribosomes, a plasma membrane, and a cell wall, with additional features like capsules, pilli, and flagella.
Capsules are polysaccharide layers providing protection, while pilli assist in adhesion, especially important for pathogenic bacteria.
Flagella in prokaryotes differ in structure from those in eukaryotes, being made of flagellin in bacteria.

Eukaryotic Cell Organelles

The nucleus stores genetic information, where DNA transcription occurs, and messenger RNA is transported via nuclear pores.
Peroxisomes breakdown hydrogen peroxide and reactive oxygen species, fatty acids, and amino acids, with special functions in seed germination.
Centrosomes, containing centrioles, serve as microtubule organizing centers during mitosis; absent in plant cells.

Vacuoles and Their Functions

Both plant and animal cells contain vacuoles for nutrient storage, though plant cells have a prominent central vacuole primarily for water storage.
The large central vacuole in plant cells may occupy over half the cell volume, maintaining turgor pressure.

Chloroplasts and Photosynthesis

Chloroplasts are membrane-bound organelles in plant cells where photosynthesis occurs; they contain their own DNA supporting endosymbiotic theory.

Summary of Cell Wall Differences

Plant cell walls are made of cellulose, fungal cell walls from chitin, and bacterial cell walls from peptidoglycan.
Prokaryotes and eukaryotes differ in cell wall composition, influencing strength, rigidity, and resistance to osmotic stress.

Cell Types and Structure

Prokaryotes are unicellular organisms without a nucleus (e.g., bacteria).
Eukaryotes possess a membrane-bound nucleus (e.g., fungi, plant, and animal cells).
Prokaryotic cells have a single circular chromosome located in the cytoplasm, whereas eukaryotic cells have multiple linear chromosomes within the nucleus.
Eukaryotic chromosomes end with telomeres, while prokaryotic chromosomes do not.

Organelles and Components

Prokaryotes lack membrane-bound organelles like mitochondria, chloroplasts, endoplasmic reticulum, and Golgi apparatus.
Ribosomes, present in both cell types, are crucial for protein synthesis.
Eukaryotic ribosomes can be free or associated with the rough endoplasmic reticulum (rough ER).
The endoplasmic reticulum includes:
- Rough ER: Studded with ribosomes, synthesizes glycoproteins for membrane integration or secretion.
- Smooth ER: Lacks ribosomes, involved in lipid synthesis, steroid hormone production, and toxin breakdown in liver cells.

Golgi Apparatus

Functions as the shipping and packaging center of the cell.
Receives proteins from the rough ER, modifies them further (e.g., glycosylation), and dispatches them to their destinations.

Mitochondria and Energy Production

Mitochondria are exclusive to eukaryotic cells and play a key role in ATP synthesis.
Prokaryotes primarily rely on glycolysis for energy production, while eukaryotes utilize glycolysis followed by the citric acid cycle and electron transport chain for efficient ATP generation.

Peroxisomes

Organelles responsible for breaking down hydrogen peroxide and other reactive oxygen species.
Involved in the breakdown of fatty acids and amino acids, and also detoxify various substances.
The glyoxylate cycle occurs in germinating seeds, aiding in the production of larger carbohydrates.

Centrosomes and Cell Division

Centrosomes consist of a pair of centrioles and act as microtubule organizing centers (MTOCs) during cell division.
The spindle apparatus is formed from microtubules originating from centrosomes.

Vacuoles

Vacuoles are membrane-bound structures found in both plant and animal cells for nutrient storage.
Plant cells typically contain a large central vacuole that maintains turgor pressure, primarily storing water and nutrients.
Vacuoles play a crucial role in maintaining cell homeostasis and storage functions across different cell types.

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Description

This quiz focuses on understanding the fundamental differences between prokaryotic and eukaryotic cells. Explore cellular structures, functions, and the importance of the nucleus in cellular biology. Test your knowledge on the characteristics of bacteria, fungi, plant, and animal cells.