Chapter 4: Evolutionary Origin of Cells and Their General Features

Cell Theory

1. All living organisms are composed of one or more cells. 2. Cells are the smallest units of life. 3. New cells come only from pre-existing cells by cell division.

Function of Cell Wall

1. Supports and protects the plasma membrane and cytoplasm. 2. Its porous structure allows most nutrients to reach the plasma membrane.

In the cilia and flagella of most eukaryotes, the microtubules are arranged in a "9 + 2" array. This refers to the presence of: 9 central single microtubules and 2 outer doublet microtubules 9 outer doublet microtubules and 2 central single microtubules 9 central doublet microtubules and 2 outer single microtubules 9 outer single microtubules and 2 central doublet microtubules

9 outer doublet microtubules and 2 central single microtubules

Which statement best describes the cytosol? A central region that coordinates many metabolic activities An external region that aids in cell movement A central region that contains the genetic material An external region that protects the cytoplasm

A central region that coordinates many metabolic activities

Which statement best describes the cytosol? A central region that coordinates many metabolic activities An external region that aids in cell movement An external region that protects the cytoplasm A central region that contains the genetic material

A central region that coordinates many metabolic activities

Cytoplasm

A jellylike fluid inside the cell in which the organelles are suspended

Polypeptides

A linear organic polymer consisting of a large number of amino-acid residues bonded together in a chain, forming part of (or the whole of) a protein molecule

Which of the following describes an organelle? Multiple choice question. A membrane-bound structure on the outside of all cells The site of protein synthesis A membrane-bound component with its own unique structure and function.

A membrane-bound component with its own unique structure and function.

Cell wall

A rigid structure that surrounds the cell membrane and provides support to the cell

Plasma Membrane

A selectively-permeable phospholipid bilayer forming the boundary of the cells

Which of these statements best describes actin filaments?

A spiral of two intertwined strands of protein

Enzyme

A type of protein that speeds up a chemical reaction in a living thing

How big is a typical eukaryotic cell? About 100-200 μm in diameter About 10-100 μm in diameter About 200-500 μm in diameter About 1-10 μm in diameter

About 10-100 μm in diameter

Function of Chloroplasts

Aid in photosynthesis

Vacuoles

Appear to be empty compartments yet contain fluid and sometimes solid substances. Many made from fusion of smaller membrane vesicles.

Glycosylation

Attachment of carbohydrates to proteins and lipids.

Motor Proteins

Category of proteins that use ATP as a source of energy to promote various types of movements

Centrioles

Cell organelle that aids in cell division in animal cells only

What best explains why most cells are small?

Cells must be small to be able to take up nutrients efficiently.

Ribosome subunits

Cellular structures involved in producing polypeptides during the process of translation

Cilia and flagella are two types of cell appendages that use which of these to facilitate movement? Actin filaments and motor proteins Microtubules and intermediate filaments Microtubules and motor proteins

Cilia and flagella are two types of cell appendages that use which of these to facilitate movement?

Axoneme

Core of eukaryotic cilia and flagella consisting of microtubules, the motor protein dynein, and linking proteins

Basal Body/Centriole

Cylindrical organelle near the nucleus. Occurs in pairs.

Select all the locations where ribosomes can be found in the cell. Cytosol Endoplasmic reticulum Golgi apparatus Chloroplasts Central vacuole mitochondria

Cytosol Endoplasmic reticulum Chloroplasts Mitochondria

Nuclear envelope

Double membrane structure that encloses the nucleus

Mitochondria

Enclosed in double membrane. Appears threadlike or granular shaped. Similar to bacteria in size. Contains an inner and outer membrane separated by intermembrane space. Forms cristae in inner membrane.

Chloroplasts

Enclosed in double membrane. Has a thylakoid membrane system so it forms flattened compartments, stack on each other to form grana. Green pigment.

What cells have membrane-bound organelles to compartmentalize functions? Neither prokaryotic nor eukaryotic cells Both prokaryotic and eukaryotic cells Prokaryotic cells only Eukaryotic cells only

Eukaryotic cells only

Differential Gene Regulation

Every cell expresses a unique set of mRNAs. These mRNAs are then translated to produce a specific set of polypeptides that form proteins

Compartmentalization

Feature of eukaryotes; membrane-bound organelles that separate the interior of the cell into different regions

Nuclear pores

Formed where the inner and outer nuclear membranes make contact with each other. Nuclear pore complexes provide a passageway for the movement of molecules and macromolecules into and out of the nucleus.

Function of Peroxisomes

Function: 1. Catalyze variety of chemical reactions including reactions that break down organic molecules and others.

Function of Smooth ER

Function: 1. Metabolism 2. Storage of Ca2+ 3. Lipid synthesis and modification

Function of Rough ER

Function: 1. Protein sorting 2. Insertion of membrane proteins 3. Glycosylation

Function of Vacuoles

Function: 1. Stores large amount of water, enzymes, and inorganic ions. 2. Space filler - exerts pressure on the cell wall called turgor pressure which maintains the structure of the cell. 3. Degradation.

Function of Lysosomes

Function: Break down molecules with hydrolytic enzymes that use water to break a covalent bond (hydrolysis)

Function of Mitochondria

Function: 1. Primary role is to generate ATP convert chemical energy from organic molecules into form that can be used by cells. 2. Contributes in synthesis, medication, and breakdown of cellular molecules.

Function of Golgi apparatus

Function: Responsible for protein sorting, processing through glycosylation or proteolysis, and secretion

Which of the following organisms are eukaryotes? Fungi Bacteria Animals Plants Archaea

Fungi Animals Plants

Pili

Hairlike projections that allow cells to attach to surfaces and to each other

Motor Protein domains

Head: the site where ATP binds and is hydrolyzed to adenosine diphosphate (ADP) and inorganic phosphate (Pi) Hinge: the site that bends in response to ATP binding and hydrolysis. This bending is what causes movement to occur. Tail: an elongated region that is attached to other proteins or to other kinds of cellular molecules

List the three different types of protein filaments that make up the cytoskeleton: Enzyme filaments Intermediate filaments Microtubules Actin

Intermediate filaments Microtubules Actin

Function of Basal Body/Centriole

Involved in development of spindle fibers during cell division

Smooth ER

Lacks ribosomes

Which of the following is the best reason for cells being small? Larger cells would require more nutrients and there is usually a limited supply. Larger cells would not be able to get necessary gases and nutrients quickly enough. Larger cells would create too much heat and enzymes will denature. The cell membrane can only stretch so much and so cannot accommodate the larger size.

Larger cells would not be able to get necessary gases and nutrients quickly enough.

Which of the following mechanisms is thought to play a role in the formation of droplet organelles? Cellular abiogenesis Passive compartmentalization Secondary endosymbiosis Liquid-liquid phase transition

Liquid-liquid phase transition

Nucleoid

Location where the genetic material (DNA) is found. It is not a membrane-bound compartment.

Flagella

Long appendages that provide prokaryotic cells with a way to move, also called motility

Centrosome

Microtubule-organizing center

Which of the following are examples of fungi? Paramecia Algae Molds Yeasts

Molds Yeasts

Rough ER

Network of membranes that form flattened, fluid filled tubules. Studded with ribosomes

Where is the DNA housed in a bacterial cell?

Nucleoid region

List the cell structures within the bacterial cytoplasm that are visible via an electron microscope. Nucleus Nucleoid region ribosomes amino acids

Nucleoid region ribosomes

Glycocalyx

Outer viscous covering surrounding many species of bacteria. The glycocalyx traps water and helps protect bacteria from drying out

Which of these organisms are examples of protists?Paramecia Bacteria Mushrooms Yeasts Algae

Paramecia Algae

Catabolism

Pathways that involve the breakdown of a molecule into smaller components

Peroxisomes

Peroxisomes are small organelles found in all eukaryotic cells. Consist of singe membrane that encloses lumen. Many are found in liver of animal cells.

What structures allow bacteria to attach to surfaces as well as to each other?

Pilli

Which of these cell structures within the bacterial cytoplasm is(are) not visible via an electron microscope?

Plasmids

Function of nucleus

Protection, organization, replication, and expression of the genetic material.

Function fo Cytoskeleton

Provide shape to the cell and aid in movement.

The internal environment of droplet organelles differs chemically from that of the surrounding medium. This may affect processes such as: 'RNA folding DNA denaturation sugar catabolism protein maturation

RNA folding

Cytosol

Region of a eukaryotic cell that is outside the membrane-bound organelles but inside the plasma membrane

What structure functions in polypeptide synthesis?

Ribosome

Cell Wall

Rigid and porous structure. Contains mostly peptides and carbs.

Cilia

Shorter than flagella and tend to cover all or part of the surface of a cell. Produce movement similarly to flagella

Lysosomes

Small organelles found in animal cells.

Vesicles

Small, membrane-enclosed sphere by which other organelles of the endomembrane system pass materials to each other

Golgi apparatus

Stack of flattened membranes, each of which encloses a cisterna

Metabolism

Sum of the chemical reactions by which cells produce the materials and utilize the energy necessary to sustain life

Anabolism

Synthesis of molecules and macromolecules

Cytoskeleton

System of protein filaments. Composed of microtubules, microfilaments, and intermediate filaments.

Endoplasmic Reticulum

The endoplasmic reticulum is composed of a network of flattened tubules called cisternae that enclose a continuous ER lumen

Cell Biology

The study of individual cells and their interactions with each other

What are the functions of the capsules that some bacteria produce? They aid in attachment to cell surfaces. They synthesize polypeptides. They prevent animals' immune systems from destroying bacterial cells. They aid in motility They substitute for the cell wall and protect from osmotic lysis.

They aid in attachment to cell surfaces. They prevent animals' immune systems from destroying bacterial cells.

What are the functions of the capsules that some bacteria produce? They aid in motility They aid in attachment to cell surfaces. They substitute for the cell wall and protect from osmotic lysis. They prevent animals' immune systems from destroying bacterial cells. They synthesize polypeptides.

They aid in attachment to cell surfaces. They prevent animals' immune systems from destroying bacterial cells.

Actin Filaments

Thin type of protein filament composed of actin proteins that forms part of the cytoskeleton and supports the plasma membrane: plays a key role, in shape, movement, and cell strength. Highly concentrated near the plasma membrane

Endomembrane system

This system includes nuclear envelope, which encloses the nucleus, as well as the endoplasmic reticulum, Golgi apparatus, lysosomes, vacuoles, peroxisomes and plasma membrane.

Ribosomes

Tiny organelles that link amino acids together to form proteins

Which of these is a reason for catabolism? To synthesize carbohydrates To glycosolate a molecule To provide building blocks To synthesize proteins

To provide building blocks

Identify the two reasons that catabolism is necessary. To utilize energy To provide building blocks To synthesize molecules

To utilize energy To provide building blocks

Select all of the statements that explain how different cells in the same organism produce different proteomes. Multiple select question. Two different cell types may produce different amounts of the same protein. Different cell types may alter their proteins in different ways. There may be differential gene regulation and alternative splicing. Different cells in the same organism have different genes. Different cells can use different types of ribosomes for translation.

Two different cell types may produce different amounts of the same protein. Different cell types may alter their proteins in different ways. There may be differential gene regulation and alternative splicing.

Microtubules

Type of hollow protein filament composed of tubulin proteins that is part of the cytoskeleton and is important for cell shape, organization, and movement

Intermediate Filaments

Type of protein filament in the cytoskeleton that functions as tension bearing fibers which helps maintain shape and rigidity of the cell

Flagella

Typically found in pairs. Produce movement by generating bends that move along the length and push backwards against the surrounding fluid

Nucleolus

Where the assembly of ribosome subunits occurs

Is it possible for cells from the same multicellular organism to have different proteomes? Yes, because cells have different structures. No. All cells from the same organism have the same proteome. Yes, because cells contain different genes. Yes, because cells produce different proteins.

Yes, because cells produce different proteins.

Is it possible for cells from the same multicellular organism to have different proteomes? Yes, because cells have different structures. Yes, because cells produce different proteins. No. All cells from the same organism have the same proteome. Yes, because cells contain different genes.

Yes, because cells produce different proteins.

The size of a larger organism is usually attributed to: cells that are much larger cells that contain more than one nucleus cells that have a small surface area to volume ratio a greater number of cells

a greater number of cells

The size of a larger organism is usually attributed to:cells that have a small surface area to volume ratio cells that are much larger cells that contain more than one nucleus a greater number of cells

a greater number of cells

When compared to a mouse, an elephant has: roughly the same number of cells, but these cells are very large about the same-sized cells, but many more of them

about the same-sized cells, but many more of them

An enzyme is a protein that ______ the rate of a chemical reaction.

accelerates

Microfilaments is another name for

actin filaments

The head of a motor protein is where ______ causing a bend in the hinge. adenosine triphosphate (ATP) binds and is hydrolyzed to ADP adenosine diphosphate (ADP) binds and is hydrolyzed to ATP

adenosine triphosphate (ATP) binds and is hydrolyzed to ADP

What are the building blocks of proteins?

amino acids

Cellular molecules and macromolecules are produced by:

anabolism

The synthesis of cellular molecules and macromolecules occurs via a process termed . _____________

anabolism

The synthesis of cellular molecules and macromolecules occurs via a process termed __________

anabolism

Flagella and cilia have an internal structure called a(n) ______ , which contains microtubules, dynein, and linking proteins.

axoneme

Some bacteria produce a thick, gelatinous glycocalyx called a(n) ______, which aids in attachment and prevent their destruction by the host immune system.

capsule

What are the common components of the prokaryotic cell wall?- think, carberry is peppy carbohydrates nucleic acids phospholipids peptides

carbohydrates and peptides

______ consists of the metabolic reactions that break down larger molecules into smaller components.

catabolism

Nearly all species of archaea and bacteria have rigid ______ ________ that supports and protects the plasma membrane and cytoplasm.

cell wall

Within the centrosome, there is a pair of structures arranged perpendicular to each other called the

centrioles

Nondividing animal cells contain a single structure near their nucleus called the _____________-, or microtubule-organizing center.

centrosome

What structure is found in plant cells but not in animal cells? Centriole Chloroplast Chromatin Mitochondrion

chloroplasts

Basal bodies are anchored to the exterior side of the plasma membrane centrosome golgi apparatus cytoplasmic side of the plasma membrane

cytoplasmic side of the plasma membrane

Intermediate filaments and actin compose this cell structure: cytoskeleton ribosome chloroplast cytoplasm

cytoskeleton

Intermediate filaments and actin compose this cell structure:] cytoplasm chloroplast ribosome cytoskeleton

cytoskeleton

In eukaryotes, the ______is the region of a eukaryotic cell that is outside the membrane-bound organelles but inside the plasma membrane.

cytosol

The location of the cytoskeleton is primarily in the ____________ but also in the nucleus along the inner nuclear membrane.

cytosol

What term describes the region of a eukaryotic cell that is outside the membrane-bound organelles but inside the plasma membrane?

cytosol

the ___ is the region that is enclosed by the plasma membrane but outside the organelles. It is the location of chemical reactions by which cells produce the materials and utilize the energy necessary to sustain life.

cytosol

The cytoskeleton is located in the: chloroplast cytosol nucleus ribosome

cytosol nucleus

Some organelles form when aggregated solutes, such as proteins and RNA molecules, separate from the bulk solvent and form a complex. These are called ________________organelles.

droplet organelle

The main function of the glycocalyx is to prevent a bacterium from:

drying out

What term describes the oscillation of a single microtubule between growing and shortening phases? Dynamic oscillation Dynamic instability Dynamic variability

dynamic instability

Which protein is activated to walk toward the basal body of the microtubules during the bending of flagella and cilia? Tubulin Dynein Myosin Actin

dynein

In eukaryotes, the endoplasmic reticulum, Golgi apparatus, lysosomes, vacuoles, nuclear envelope, and plasma membrane form a network of membranes called the _____ _____

endomembrane

a ______ is a protein that accelerates the rate of a chemical reaction.

enzyme

Aside from bacteria and archaea, all other species are .

eukaryote

True or false: All of the cells of a given species have the same shape, size, and organization.

false

True or false: Plant and animal cells have identical internal organelles and structures.

false

What is used by prokaryotes to move? Cilia Motility organ Prokaryotes move by fluid convection only Flagella

flagella

___ are long, threadlike structures, which are used to provide motility to bacterial cells.

flagella

____ are appendages used by prokaryotic cells to move.

flagella

The two types of cell appendages that use microtubules and motor proteins to facilitate movement are ______ and _______-

flagella and cilia

Cisternae

flattened stacked membrane folds

As the volume of a cell increases, the surface area/volume ratio:

gets smaller

The outer gelatinous covering surrounding some bacteria is called the:

glycocalyx

Genetic material can be found in all of these organelles except:

golgi apparatus

List the three domains of a motor protein. hinge tail head middle

hinge] tail head

A _____ filament has a staggered alignment of different proteins such as keratin and lamin and may be found in such places as skin and kidney cells.

intermediate

What property of the cell wall allows nutrients in the environment to reach the plasma membrane?

it is pourous

Droplet organelles are a recently-discovered phenomenon. They are not surrounded by any membranes. Rather, they form via a mechanism called______________ -_____________ _______________ separation.

liquid-liquid phase

What term describes the chemical processes that occur within living cells in order to maintain life?

metabolism

______________ is defined as the sum of the chemical reactions by which cells produce the materials and utilize the energy that is necessary to sustain life.

metabolism

__________are long, hollow, cylindrical structures about 25 nm in diameter and composed of the protein tubulin.

microtubules

What property do flagella provide to bacterial cells?

motility

______ proteins are a category of proteins that use ATP as a source of energy to promote various types of movements.

motor proteins

The nucleus is enclosed by a double membrane structure called the __________ ___________--

nuclear envelope

The double membrane structure that surrounds the nucleus is the: plasma membrane nuclear envelope nuclear matrix

nuclear matrix

In bacteria, the genetic material is located in a region of the cytoplasm called the .

nucleoid

Which of the following is an example of a droplet organelle? Leukoplast Nucleolus Peroxisome Lysosome

nucleous

In bacteria, the genetic material is located in a region of the cytoplasm called the

nucleuoid region

In eukaryotic cells, most of the DNA is housed in an internal compartment, or organelle, called the (one word).

nucleus

The______- is an organelle in eukaryotic cells that contains most of the cell's genetic material.

nucleus

Where is most of the DNA located in a eukaryotic cell?

nucleus

the _____ is an organelle in eukaryotic cells that contains most of the cell's genetic material.

nucleus

The general term used to describe a membrane-bound structure within a cell that has its own unique structure and function is .

organelle

Eukaryotic cells have many membrane-bound compartments called____ , whereas prokaryotic cells do not exhibit compartmentalization.

organelles

What are the common components of the prokaryotic cell wall? Peptides Phospholipids nucleic acids carbohydrates

peptides carbohydrates

Although cell wall composition varies widely amongst prokaryotes, they commonly contain

peptides and carbohydrates

Hairlike projections on bacterial cells called _______allow bacteria to attach to surfaces as well as to each other.

pili

Hairlike projections on bacterial cells called_____allow bacteria to attach to surfaces as well as to each other.

pilli

What describes the cell wall of prokaryotic cells? impermeable to most nutrients studded with special protein channels strictly impermeable and water-tight relatively porous

pourus

All the proteins in a cell make up the:

proteome

The complete protein composition of a cell or organism is called the .

proteome

What describes the cell wall of prokaryotic cells? relatively porous impermeable to most nutrients studded with special protein channels strictly impermeable and water-tight

relatively porous

Droplet organelles provide an environment where molecules that are brought closer together can easily accumulate into complexes. An example is the assembly of ____________subunits in the nucleolus.

ribosomal

Structures called_______ are found in both prokaryotic and eukaryotic cells and are the sites of polypeptide synthesis.

ribosomes

Translation occurs on ________, which are found in various locations in the cell.

ribosomes

The cell walls of most bacteria and archaea are

rigid

Select all of the following that can vary in the cells of eukaryotic species. Multiple select question. type of nucleic acid used to store genetic information shape size types of organelles

shape size types of organelles

Catabolism involves the breakdown of a molecule into ______ components.

smaller

Cells are typically small because as cell size increases, the surface area and volume increase at the same rate. the volume and surface area decrease. the surface area increases faster than the volume. the volume increases faster than the surface area.

the volume increases faster than the surface area.

The process by which proteins are made using the information within an mRNA is called .

translation

What is the process of polypeptide synthesis?

translation

True or false: Dynamic instability means that a single microtubule can oscillate between growing and shortening phases.

true

The process by which proteins are made using the information within an mRNA is called. actin tubulin peptin flagellin

tubulin