Biology Chapter 1: Cell Structure and Function

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Questions and Answers

What is the definition of a cell in a biological context?

A device designed for processing data in computers.

A confined space used to detain individuals.

A small room used by monks for solitude.

The smallest unit of matter capable of independent life. (correct)

Which statement about the relationship between cells is true?

Every organism is made of a single type of cell.

All cells have originated from earlier cells. (correct)

All cells are entirely independent of each other.

Cells cannot reproduce or evolve.

What does the phrase 'cell structure is correlated to cellular function' imply?

Different cell types share the same structure and function.

The functionality of a cell is linked to its specific structural components. (correct)

All cells have identical functions regardless of structural differences.

Cell function is determined randomly regardless of structure.

What is the main aim of the lecture according to the content provided?

To provide an overview of cell structure and the role of organelles. Signup and view all the answers

Which analogy is made in the lecture introduction to emphasize the quest for knowledge?

A journey without a destination. Signup and view all the answers

What is one of the main functions of the extracellular matrix (ECM) in animal cells?

Coordinating cellular activities Signup and view all the answers

Which component is essential for a macrophage's ability to destroy bacteria?

The plasma membrane for engulfing bacteria Signup and view all the answers

How do cells relate to each other according to cellular evolution?

All cells are related by their descent from earlier cells Signup and view all the answers

What role does the endomembrane system play in eukaryotic cells?

It regulates protein traffic and metabolic functions Signup and view all the answers

What is the primary function of mitochondria and chloroplasts in eukaryotic cells?

Conversion of energy from one form to another Signup and view all the answers

Which feature is shared by both prokaryotic and eukaryotic cells?

Plasma membrane Signup and view all the answers

What do differential gene expression and signaling result in?

Development of multiple cell types Signup and view all the answers

What is the size of the first organisms that were single-celled?

1 μm Signup and view all the answers

Which domain includes organisms such as plants, fungi, and animals?

Domain Eukarya Signup and view all the answers

Which characteristic is NOT typically associated with prokaryotic cells?

Presence of organelles Signup and view all the answers

What serves as evidence for a common ancestor among organisms?

Common cellular structures Signup and view all the answers

What is the approximate size of a typical eukaryotic cell?

100 μm Signup and view all the answers

What is the main function of ribosomes found in both prokaryotic and eukaryotic cells?

Synthesize proteins Signup and view all the answers

What type of cytoplasm allows for amoeboid movement by forming extended pseudopodia?

Gel Signup and view all the answers

What key structure controls the beating of cilia and flagella in cells?

Dynein proteins Signup and view all the answers

How do cilia and flagella differ in motion?

Cilia move in a coordinated back-and-forth pattern, unlike flagella. Signup and view all the answers

Which components are responsible for the curving motion of cilia and flagella?

Dynein arms and protein cross-links Signup and view all the answers

In muscle cells, which proteins interact to facilitate contraction?

Actin and myosin Signup and view all the answers

Which of the following accurately describes the structure of cilia?

Cilia are made up of outer microtubule doublets and a central microtubule. Signup and view all the answers

What role do cross-linking proteins play in the motion of cilia and flagella?

They limit the sliding of outer doublets, aiding in bending. Signup and view all the answers

What is the primary function of the actin filament in a muscle cell?

To facilitate contraction with myosin Signup and view all the answers

Which of the following best describes the movement characteristics of flagella?

A smooth wavelike motion in one direction Signup and view all the answers

Which statement about the inner and outer cytoplasm in amoeboid movement is true?

The outer cytoplasm has a network of actin, while the inner is made of sol. Signup and view all the answers

What is the primary function of the central vacuole in plant cells?

Hold organic compounds and water Signup and view all the answers

Which cellular structure is responsible for protein synthesis?

Ribosomes Signup and view all the answers

What defines the nuclear envelope?

Contains nuclear pores Signup and view all the answers

Which organelles are primarily involved in energy transformation within cells?

Mitochondria and chloroplasts Signup and view all the answers

How do mitochondria and chloroplasts resemble bacteria?

They contain circular DNA and ribosomes Signup and view all the answers

What process forms food vacuoles in cells?

Phagocytosis Signup and view all the answers

What is a primary role of contractile vacuoles in freshwater protists?

Pump excess water out of cells Signup and view all the answers

Which component is found in the nuclear envelope?

Lipid bilayer Signup and view all the answers

What is a distinguishing feature of prokaryotic cells compared to eukaryotic cells?

Lack of membrane-bound organelles Signup and view all the answers

Which organelle is responsible for producing energy in eukaryotic cells?

Mitochondrion Signup and view all the answers

Which structure is unique to plant cells and not found in animal cells?

Cell wall Signup and view all the answers

Which statement accurately describes the function of the cell membrane?

Regulates the movement of substances in and out of the cell Signup and view all the answers

What structure is primarily involved in ribosome production within a eukaryotic cell?

Nucleolus Signup and view all the answers

Which type of eukaryotic cell lacks chloroplasts?

Animal cells Signup and view all the answers

What is the function of vacuoles in plant cells?

Storage of substances Signup and view all the answers

Which cellular structure is composed of microtubules and provides support and shape to the cell?

Cytoskeleton Signup and view all the answers

How do yeast cells reproduce?

Budding Signup and view all the answers

What distinguishes cells with flagella from those without?

Locomotion capabilities Signup and view all the answers

Study Notes

Lecture 1: Introduction: Evolution of Cells and Classification of Organisms

The lecture is about the evolution of cells and classification of organisms.
The lecturer is Dr. Leonid Nikitenko.
Contact email: [email protected]
Module code: 441287 Cell Structure and Function.
Date of lecture: 24/09/24
Level 4 module.
The class size is 150 students
The teaching team comprises 6 members whose percentages range from 1% to 90%.

Module 441287 Cell Structure and Function

The module aims to provide insight into the evolution and classification of organisms.
The module will cover a brief overview of cell structure and the roles of individual organelles in cell function.

Cell: The ∞ quest for knowledge

The lecture aims to present a comprehensive overview of cells, addressing questions like 'Why?', 'What?', 'How?', 'Who?', and 'Where?'
A quote from Lewis Carroll is provided: "That depends a good deal on where you want to get to."
There is a Canvas discussion section available for further interaction

Lecture Aims

The lecture aims to educate on aspects of cell evolution and organism classification.
A brief overview of cell structure and the function of individual organelles will be discussed.

What is Cell?

A cell is the basic functional, structural, and biological unit of all living organisms.
Other definitions include a small room in which a monk lives, a microprocessor architecture, or a prison cell.
Diagrams of a cell and its parts, such as the nucleus, plasma membrane, endoplasmic reticulum, ribosomes, mitochondria, Golgi apparatus, lysosomes, vacuoles, microfilaments, microtubules, intermediate filaments, peroxisome are discussed

Overview: Cells - The Fundamental Units of Life

All organisms are composed of cells.
A cell is the most basic unit of life
All cells are related through descent from previous cells.
Cell structure is closely related to its function.

Cell: The basis/foundation and diversity

Cells form a fundamental basis for organism development and existence, displaying intricate diversity.
Diagrams of various stages in developmental processes, including zygote, blastula, gastrula, and organismal structure are shown.
The development of organisms from simple to complex is shown.

Multicellular Organisms and Various Cell Types

A single genome can give rise to multiple different cell types and tissues
Differential gene expression leads to differential cell signalling pathways in multicellular organisms.

From cell to tissues, organs, organ systems and organism

Focuses on the hierarchical organization from cells to organisms, highlighting the continuous process in multicellular life forms.
Diagrams illustrating the progressive levels of organization from cells to tissues and culminating in organ systems and complete organisms are presented in the lecture.

Various multicellular organisms and models

Various multicellular organisms and models, such as fish, human beings and mice etc., are presented to illustrate the variety and diversity in the animal kingdom, which highlights the complexity of the variety in cell types and structures of organisms.
Diagrams of cells and their structures and various organisms.

The Three Domains of Life

Life is categorized into three domains: Bacteria, Archaea, and Eukarya.
Within Eukarya, there are different kingdoms like Animals, Fungi, and Protists.
Images of the organisms and diagrams are shown.

Hierarchical Classification

A hierarchical system classifying organisms from species to domain is depicted.
A specific example of the American black bear (Ursus americanus) is used to illustrate the hierarchical levels.

Cell Evolution: A Brief History of (Cell) Time

The first organisms were single-celled.
Fossils of bacteria-like organisms are at least 3 billion years old.
Evidence presented for a common ancestor of all life forms, showing common features, such as common biochemical building blocks, common patterns of metabolism, and common genetic code

Example: Presence of common cellular structures

Examples of common cellular structures, such as cilia from paramecium and windpipe cells, are discussed.
Microscopic images of these structures are presented for reference
The size of a cilium is given using electron microscope

Comparing Prokaryotic and Eukaryotic Cells

Comparing features of prokaryotic and eukaryotic cells is presented
Basic features in cells are compared from prokaryotic to eukaryotic, highlighting fundamental cell structures

Sizes of the cells and organelles

A comparison of the sizes of different cells and organelles is presented with images.

Common features of Prokaryotes and Eukaryotes

Cells share fundamental features: plasma membrane, semifluid substance (cytosol), chromosomes, and ribosomes

Prokaryotes and Eukaryotes

Images of typical rod-shaped bacteria and mammalian cells are shown.

Exploring Eukaryotic Cells

Various eukaryotic cells, including animal cells and fungal cells, and their components, such as yeast cells budding are shown.

Cells with Chloroplasts

Specific images of plant and protistan cells showing chloroplasts, cell walls, and other specific features are shown.

Specific cell types (Spermatozoa)

Diagrams of spermatozoa are presented.
The structure of a sperm cell is described (oval head and tail).

Cell Organelles

Diagrams illustrating various cell organelles and their respective functions, such as nucleus, rough and smooth endoplasmic reticulum, golgi apparatus, mitochondria, peroxisomes, and chloroplast

Cell Membrane

The cell membrane's functions include protection, maintaining cellular integrity, and providing a selective barrier; allowing interaction with other cells and offering flexibility.
A detailed diagram of the cell membrane structure is shown (hydrophilic head, hydrophobic tail, cholesterol, phospholipids, glycoprotein, etc.).

Vacuoles: Diverse Maintenance Compartments

Food vacuoles are formed by phagocytosis.
Contractile vacuoles help in pumping out excess water in freshwater protists.
Central vacuoles are found in plant cells, playing roles in storage and water balance
Images of these structures from plants and protists.

The Nucleus: Information Central

The nucleus is a conspicuous organelle housing the cell's DNA.
It houses chromosomes, containing most of the cell's genes, and the nuclear envelope.
A diagram of the nucleus structure is presented.

The Endomembrane System

The endomembrane system regulates protein traffic and performs metabolic functions within the cell, including the endoplasmic reticulum, Golgi apparatus, lysosomes, and exosomes
An overview of functions of different component of endomembrane system is presented with images.

Ribosomes: Protein Factories

Ribosomes, the protein-synthesizing machinery in the cell, consist of two subunits.
Ribosomes are found both in the cytosol and attached to the endoplasmic reticulum and nuclear envelope.

Mitochondria and chloroplasts change energy from one form to another

Mitochondria are sites for cellular respiration, generating ATP.
Chloroplasts are found in plants and algae, carrying out photosynthesis.
Peroxisomes are oxidative organelles.

The Evolutionary Origins of Mitochondria and Chloroplasts

Mitochondria and chloroplasts have similarities with bacteria, being enveloped by a double membrane, having free ribosomes and circular DNA, and growing and reproducing somewhat independently in cells.

The Endosymbiont theory

Explains the origin of mitochondria and chloroplasts through endosymbiosis
It suggests that early eukaryotic cells engulfed nonphotosynthetic or photosynthetic prokaryotic organisms.
Explanation and diagram of the evolutionary process.

Extracellular components and connections between cells help coordinate cellular activities

Extracellular components and connections enable coordination in multicellular organisms.
Examples include cell walls of plants, the extracellular matrix (ECM), and intercellular junctions.

The Cell: A Living Unit Greater Than the Sum of Its Parts

Cells depend on the integrated functioning of various structures and organelles; for example, a phagocytic cell like a macrophage depends on the coordinated efforts of cytoskeleton, lysosomes, and the plasma membrane
The interactive nature of the cell parts and structures to create the complete cell function is explained

The summary (I)

The lecture aims to provide insight into the evolution and classification of organisms.
The lecture will cover a brief overview of cell structure and the role of individual organelles in cell function.

The summary (II)

All organisms are made up of cells.
A cell is the simplest unit of life.
All cells are related by descent from earlier cells
Cell structure directly correlates to cellular function.

The summary (III)

The eukaryotic cell's genetic instructions are housed in the nucleus and carried out by ribosomes
The nucleus is described as the control centre of the cell and the chromosomes as the genetic material housed within
The ribosomes synthesize proteins

The summary (IV)

The endomembrane system regulates different cellular activities including protein traffic and various metabolic functions.
The system involves specific components like the endoplasmic reticulum, Golgi apparatus, and lysosomes
Detailed functions of each component are described.

The summary (V)

Mitochondria and chloroplasts were originally bacteria, and these organelles convert energy from one molecular form to another within cells.
Mitochondria carry out cellular respiration, while chloroplasts perform photosynthesis.

Home work: How do cells move?

Amoeboid Movement

Cytoplasmic Streaming

Cilia and Flagella

Dynein "walking"

Actin/myosin "walking"/motors

How to study Cell Structure and Function?

Review material regularly to prepare for exams
Check lecture material against aims and questions

Frequently Asked Questions

Key questions related to the lecture material ('Why?', 'What?', 'How?', 'Who?', and 'Where?') are presented.
A contact email address is provided for students with further questions or for additional discussion inquiries.

Take home message

The module content and materials are available for the students to learn about cells.

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Description

This quiz explores the fundamental concepts of cell biology, including the definition of cells, their structures, and functions. It covers the relationship between various cell types, the role of the extracellular matrix, and the similarities between prokaryotic and eukaryotic cells. Test your knowledge on these essential topics!