Biology 3 part 2

The main microtubule organizing center for a eukaryotic cell that lies near the nucleus is called the

Centrosome

Chromatin

The network of DNA stands and associated proteins observed within a nucleus of a cell

A nuclear pore is best described as a(n):

opening in the nuclear envelope that permits the passage of molecules into and out of the nucleus

Which cellular process occurs within chloroplasts?

photosynthesis.

The rough endoplasmic reticulum is studded with:

ribosomes

Nucleoplasm

Semifluid medium of the nucleus, containg chromatin

Ribosomes

Site of protein synthesis in a cell, composed of proteins and ribosomal RNA(rRNA)

Vesticle

Small, Membrane bound sac that stores substances within a cell

The process of photosynthesis occurs within organelles called

chloroplasts

The organelle that contains the genetic material in a eukaryotic cell is called the

nucleus

The organelles that function in protein synthesis are called

ribosomes.

Which organelle is formed in the Golgi apparatus?

Lysome

A protistan engulfs a macromolecule via a vesicle. Which organelle could fuse to this vesicle and aid in breaking down this molecule?

Lysomsome

A vesicle that contains hydrolytic digestive enzymes is called a

Lysosome

are the organelles that function in intracellular digestion.

Lysosomes

Which organelle is often referred to as the "power plant of the cell?"

Mitochondria

From which parent(s) are mitochondrial genes inherited?

Mother

A darkly staining region that may appear within the nucleus on an electron micrograph is called a(n) ______. This is the location of rRNA production.

Nucleolus

The semifluid material enclosed by the nuclear envelope is called

Nucleoplasm

Which of these organelles contains the genetic material in a eukaryotic cell?

Nucleus

which relate to the role of microtubules in a eukaryotic cell.

Organelle movement Cilia and flagella Cell shape

What would be the result if a cell was unable to form a spindle apparatus?

The cell would be unable to separate its chromosomes during cell division

A cell that has numerous mitochondria is most likely a cell that needs a large amount of

Energy

Peroxisomes

Enzyme-filled vesicle in which fatty acids and amino acids are metabolized to hydrogen peroxide that is broken down into harmless products.

All cells in a multicellular organism tend to have a similar number of mitochondria.

False

Plant cells do not have centrosomes.

False

True or false: Ribosomes may occur singly in the cytoplasm or in groups called Golgi bodies.

False

Which of the following are components of the cytoskeleton?

Intermediate filaments Actin filaments Microtubules

Functions of the lysosome include: (Mark all that apply)

Intracellular digestion Autodigestion

Nucleus

Membrane-bound organelle within a eukaryotic cell that contains chromosomes and controls the structure and function of the cell

Rough ER (endoplasmic reticulm)

Membranous system of tubules, vesticles, and sacs in cells, has attached ribosomes

Smooth Endoplasmic Reticulum (SER)

Membranous system of tubules, vesticles, and sacs in eukaryotic cells, site of lipid synthesis, lacks attached ribosomes.

What is the function of the centriole?

Microtubule assembly and disassembly

Centrioles

The centrioles may be involved in the process of microtubule assembly and disassembly

Which of the following are components of the endomembrane system?

The nuclear envelope Golgi apparatus Vesicles Endoplasmic reticulum

Which of the following are true about cilia?

They are shorter than flagella. They all beat together in a coordinated manner.

The nucleoplasm has a different fluid composition than the cytoplasm of a cell.

True The composition of the nucleoplasm is different than that of the cytoplasm.

Which protein forms microtubules in the cell?

Tubulin

Eukaryotic Cell ( Eukaryote)

Type of cell that has a membrane bound nucleus and membranous organelles; found in organisms within the domain Eukarya

A large membranous sac located in the cytoplasm of a cell:

Vacuole

Which of the following is larger?

Vacuole

Which of the following are components of the endomembrane system? (Mark all that apply)

Vesicles Golgi apparatus The nuclear envelope Endoplasmic reticulum

Chloroplasts use solar energy to synthesize _______ during a process called photosynthesis.

carbohydrates

The inner fluid-filled space of a mitochondrion is called the

matrix

Chromosome

the sturcture that transmits the genetic material from one generation to the next, composed of condensed chromatin; each species has a particular number of chromosomes that is passed on to the next generation.

True or false: A sperm does not contribute mitochondrial genes when fertilizing an egg.

true

Vacuoles

A vacuole is a large membranous sac. A vacuole is larger than a vesicle. Although animal cells have vacuoles, they are much more prominent in plant cells. Typically, plant cells have a large central vacuole filled with a watery fluid that provides added support to the cell

which relate to the role of microtubules in a eukaryotic cell. (Mark all that

Cilia and flagella Cell shape Organelle movement

Select the following which relate to the role of microtubules in a eukaryotic cell.

Cilia and flagella Organelle movement Cell shape

What is the the function of the mitochondria?

Convert substrates into ATP

The filaments labeled with the letter A make up the

Cytoskeleton

Which organelle receives proteins and lipid-filled vesicles from the endoplasmic reticulum and then repackages them for export in secretory vesicles?

Golgi apparatus

Energy-Related Organelles

Life is possible only because of a constant input of energy. Organisms use this energy for maintenance and growth. Chloroplasts and mitochondria are the two eukaryotic membranous organelles that specialize in converting energy to a form the cell can use. Chloroplasts use solar energy to synthesize carbohydrates, which are broken down by the mitochondria (sing., mitochondrion) to produce ATP molecules, as shown in Figure 3.10. This diagram shows that chemicals recycle between chloroplasts and mitochondria in the presence of solar energy. When cells use ATP as an energy source, energy dissipates as heat. Most life cannot exist without a constant input of solar energy. Here, energy is in the form of ATP molecules. When a cell needs energy, ATP supplies it. The energy of ATP is used for all energy-requiring processes in cells.

Chloroplasts

Plant and algal cells contain chloroplasts (Fig. 3.11), the organelles that allow them to use solar energy to produce organic molecules. A chloroplast is bounded by two membranes that enclose a fluid-filled space called the stroma (Fig. 3.11). The stroma contains a single circular DNA molecule, as well as ribosomes. The chloroplast contains its own genetic material and makes most of its own proteins. The others are encoded by nuclear genes and imported from the cytoplasm. A membrane system within the stroma is organized into interconnected flattened sacs called thylakoids. In certain regions, the thylakoids are stacked up in structures called grana (sing., granum). There can be hundreds of grana within a single chloroplast (Fig. 3.11). Chlorophyll, which is located within the thylakoid membranes of grana, captures the solar energy needed to enable chloroplasts to produce carbohydrates.

One side of the Golgi apparatus is directed toward the endoplasmic reticulum, while the other faces the

Plasma Membrane

A group of ribosomes that are attached to a single mRNA are called a

Polyribosome

The openings in the nuclear envelope through which particles may pass are called nuclear

Pores

Chromatin consists of DNA and associated:

Proteins

Which organelle is assembled in the nucleolus of the nucleus?

Ribosome

In a cell, proteins are made at structures called

Ribosomes

The rough ER differs from the smooth ER in that it is covered with:

Ribosomes

When ribosomes in a cell's cytoplasm are attached to an organelle, that organelle now studded with ribosomes is then called endoplasmic reticulum.

Rough

List, in order, the BEST sequence of organelles/structures which can be used to synthesize and secrete a particular protein from a cell.

Rough ER, Golgi, secretory vesicle

The Cytoskeleton

The cytoskeleton contains actin filaments, intermediate filaments, and microtubules, which maintain cell shape and allow the cell and its organelles to move.

The double membrane that surrounds the nucleus in eukaryotic cells and is connected to the endoplasmic reticulum is called the:

nuclear envelope

A group of ribosomes that are attached to a single mRNA is called a

polyribosome, polysome, polyribosomes, or polysomes

List, in order, the BEST sequence of organelles/structures which can be used to synthesize and secrete a particular protein from a cell. Start at the top, with the organelle that synthesizes the product.

1. Rough ER 2. Transport Vesicle 3. Golgi Apparatus 4. Secretory Vesicle

The substance consistiong of DNA and associated protiens in a eukaryotic cells's nucleus is called (A). WHen highly condensed, as it is in the preperation of a cell division, this material is called (B)

A= Chromatin B= chromosomes

Mitochondria use carbohydrates to produce:

ATP

The molecule produced by cellular respiration that is used to fuel energy dependent cellular reactions is

ATP, adenosine triphosphate, or adenosine tri phosphate

Which of the following are functions of the cytoskeleton? (Mark all that apply)

Aids in cell division Intracellular transport Cellular structural support

Where are ribosomes typically located in a cell?

Fre in the cytoplasm, Attached to the endoplasmic reticulm

Which molecule is used to fuel all energy dependent cellular processes?

Atp

What is the the function of chlorophyll?

Capture Solar energy

Which cellular organelle may function in the process of microtubule assembly and disassembly?

Centriole

From which part of a eukaryotic cell do microtubules radiate?

Centrosome

Which of these is a pigment located within the thylakoid membrane that functions to capture solar energy?

Chlorophyll

Identify the filaments of the cytoskeleton.

Choice, Actin filaments Actin filaments B matches Choice, Intermediate filaments Intermediate filaments C matches Choice, Microtubules Microtubules

Identify the structures of a chloroplast.

Choice, Double membrane Double membrane B matches Choice, Thylakoid space Thylakoid space C matches Choice, Thylakoid Thylakoid D matches Choice, Stroma Stroma E matches Choice, Grana Grana

Match the letters from the diagram to the structures in a mitochondrion.

Choice, double membrane double membrane B matches Choice, outer membrane outer membrane C matches Choice, inner membrane inner membrane D matches Choice, cristae cristae E matches Choice, matrix matrix

Chromatin, which consists of DNA and associated proteins, undergoes coiling and condenses during cell division to form

Chromosomes

Cilia and Flagella

Cilia (sing., cilium) and flagella (sing., flagellum) are hairlike projections that can move either in an undulating fashion, like a whip, or stiffly, like an oar. Some cells that have these organelles are capable of movement. For example, single-celled organisms called paramecia move by means of cilia, whereas sperm cells move by means of flagella. In the human body, the cells that line our upper respiratory tract have cilia that sweep debris trapped within mucus back up into the throat, where it can be swallowed or ejected. This action helps keep the lungs clean.

Nucleolus

Dark staining, spherical body in the nucleus that produces ribsomal subunits

Identify the structures of a chloroplast.

Double Membrane Thylakoid space thylakoid stroma grana

Nuclear envelope

Double membrane that surrounds the nucleus in eukaryotic cells and is connected to the endoplamic reticulm, has pores that allow substances to pass between the nucleus and the cytoplasm

The nuclear envelope and endoplasmic reticulum are components of the

Endomembrane system

The nuclear envelope and endoplasmic reticulum are components of the Multiple choice question.

Endomembrane system

The double membrane that surrounds the nucleus is called the nuclear

Envelope

Lysosomes

Membrane-bound vesicle that contains hydrolytic enzymes for digesting macromolecules and bacteria; used to recycle worn-out cellular organelles. When lysosomes fuse with these vesicles, the bacteria are digested. Even parts of a cell are digested by its own lysosomes (called autophagy). For example, the finger webbing found in the human embryo is later dissolved by lysosomes so the fingers are separated. Lysosomes contain many enzymes for digesting all sorts of molecules. Occasionally, a child inherits the inability to make a lysosomal enzyme, and therefore has a lysosomal storage disease. For example, in Tay-Sachs disease (see chapter opener), the cells that surround nerve cells cannot break down the lipid ganglioside GM2, which then accumulates inside lysosomes and affects the nervous system. At about 6 months, the infant can no longer see and, then, gradually loses hearing and even the ability to move. Death usually occurs by about 3 years of age.

Both cilia and flagella are composed of what type of cytoskeletal component?

Microtubules

Microtubules

Microtubules are small, hollow cylinders about 25 nm in diameter and 0.2-25 µm in length. Microtubules are made of the globular protein tubulin, which is of two types, called α and β. The regulation of microtubule assembly is controlled by a microtubule organizing center. In most eukaryotic cells, the main microtubule organizing center is in the centrosome, which lies near the nucleus. Microtubules radiate from the centrosome, helping to maintain the shape of the cell and acting as tracks along which organelles can move. Before a cell divides, microtubules disassemble and then reassemble into a structure called a spindle. The spindle apparatus attaches to the chromosomes and ensures that they are distributed in an orderly manner. It also participates in dividing the cell in half. At the end of cell division, the spindle disassembles, and microtubules reassemble once again into their former array.

Mitochondria

Mitochondria are the power plants of the cell. Substrates broken down in the cytoplasm are transported into the mitochondria and converted into ATP to be used by the cell for its various needs. Mitochondria are also involved in cellular differentiation and cell death. It is now recognized that mitochondria play a role in the aging process.Figure 3.12Mitochondrion structure. Mitochondria are involved in cellular respiration. a. Electron micrograph of a longitudinal section of a mitochondrion. b. Generalized drawing in which the outer membrane and portions of the inner membrane have been cut away to reveal the cristae. The number of mitochondria per cell can vary considerably. Some cells have only one mitochondrion, while other cells may have thousands. Tissues that need large amounts of energy have more mitochondria per cell than tissues with lower energy demand.In humans, the mother's egg supplies the mitochondria. The father's sperm typically does not contribute any mitochondria to the offspring. This has made mitochondrial DNA studies useful for population genetic studies. An interesting example of this is the search for "mitochondrial Eve," which examines different models on how early humans migrated from Africa (see Section 32.5).

Nuclear pore

Opening in the nuclear envelope that permits the passage of protiens into the nucleus and ribsomal subunits out of the nucleus

Golgi apparatus

Organelle consisting of sacs and vesicles that processes, packages, and distributes molecules about or from the cell.The Golgi apparatus is named for Camillo Golgi, who discovered its presence in cells in 1898. The Golgi apparatus consists of a stack of between 3 and 20 slightly curved sacs whose appearance can be compared to a stack of pancakes (Fig. 3.8). The Golgi apparatus is referred to as the shipping center of the cell because it collects, sorts, packages, and distributes materials such as proteins and lipids. In animal cells, one side of the stack (the inner face) is directed toward the ER, and the other side of the stack (the outer face) is directed toward the plasma membrane. Vesicles can frequently be seen at the edges of the sacs.The Golgi apparatus receives proteins and also lipid-filled vesicles that bud from the ER. These molecules then move through the Golgi from the inner face to the outer face. During their passage through the Golgi apparatus, proteins and lipids can be modified before they are repackaged in secretory vesicles. Secretory vesicles proceed to the plasma membrane, where they discharge their contents. This action is termed secretion or exocytosis. Page 53 The Golgi apparatus is also involved in the formation of lysosomes, vesicles that contain enzymes that remain within the cell.

The action known as , or exocytosis, involves the release of materials from the cell via vesicles that fuse with the plasma membrane.

Secretion

The release of cellular products from a cell is called:

Secretion

Organelle

Small, membranous structure in the cytoplasm having a specific structure and function

Which cellular organelle will attach to the chromosomes and ensures they are distributed evenly during cell division?

Spindle apperatus

Structures Of Eukaryotic Cells

StructureCompositionFunctionCell wall (plants, fungi, algae, and some protists)Contains polysacharridesSupport and protectionPlasma membranePhospholipid bilayer with embedded proteinsDefines cell boundary; regulates molecule passage into and out of cellsNucleusNuclear envelope, nucleoplasm, chromatin, and nucleoliStorage of genetic information; synthesis of DNA and RNANucleoliConcentrated area of chromatin, RNA, and proteinsRibosomal subunit formationRibosomesProtein and RNA in two subunitsProtein synthesisRough endoplasmic reticulum (RER)Network of folded membranes studded with ribosomesFolding, modification, and transport of proteins for export or associated with membranesSmooth endoplasmic reticulum (SER)Network of folded membranes having no ribosomesLipid and carbohydrate synthesis in some cells; detoxification of chemicalsGolgi apparatusStack of small membranous sacsProcessing, packaging, and distribution of proteins and lipidsLysosomes (animal cells only)Membranous vesicle containing digestive enzymesIntracellular digestion; recycling of cellular componentsVacuoles and vesiclesMembranous sacs of various sizesStorage of substancesPeroxisomesMembranous vesicle containing specific enzymesBreakdown of fatty acids and other metabolic tasksMitochondriaInner membrane (cristae) bound by an outer membraneCellular respirationChloroplasts (plant cells and some protists)Membranous grana bound by two membranesPhotosynthesisCytoskeletonMicrotubules, intermediate filaments, actin filamentsShape of cell and movement of its partsCilia and flagella (cilia are rare in plant cells)MicrotubulesMovement of cellCentriole (animal cells only)MicrotubulesCell division

Endoplasmic Reticulum (ER)

System of membranous saccules and channels in the cytoplasm, often with attached ribosomes.

The Nucleus

The nucleus is one of the defining characteristics of a eukaryotic cell. It is responsible for storing the genetic material, deoxyribonucleic acid (DNA). In the factory analogy, the nucleus is the head office. DNA governs the characteristics of the cell and thus its metabolic functions. Page 51 When you look at the nucleus, even in an electron micrograph, you cannot see a DNA molecule (Fig. 3.6). Instead, what you see is chromatin, which consists of DNA and associated proteins. Chromatin in most eukaryotic cells is not one continuous strand. During most of the cell's lifetime, chromatin is present, but when the cell is ready to undergo cell division, it will undergo coiling and become highly condensed structures called chromosomes. Human cells contain 46 chromosomes, which are immersed in a semifluid medium called the nucleoplasm. The nucleoplasm and the cytoplasm of a cell have different compositions.

Chloroplasts contain numerous structures called grana, each of which is a stack of

Thylakoid membranes

A sperm does not contribute mitochondrial genes when fertilizing an egg.

True

True or false: The Golgi apparatus produces both secretory vesicles and lysosomes.

True