chapter 6

Desmosomes

Anchoring junctions that prevents cells subjected to mechanical stress from being pulled apart; button like thickenings of adjacent plasma membranes connected by fine protein filaments

Nucleolus

Found inside the nucleus and produces ribosomes

Tight Junctions

Membranes of neighboring cells are pressed together, preventing leakage of extracellular fluid

Centrosomes

Microtubule-organizing centers that help to form and organize the mitotic spindle during mitosis

Motor Proteins

Specialized proteins that use energy to change shape and move cells or structures within cells.

Smooth ER

That portion of the endoplasmic reticulum that is free of ribosomes.

Which organelle often takes up much of the volume of a plant cell? a.) Lysosome b.) central vacuole c.) Golgi apparatus d.) chloroplast e.) Mitochondria

b

Double strands of nucleotides (DNA) wrapped around proteins is called ________________________________.

double helix

Integrins

membrane proteins; they transmit signals between the ECM and cytoskeleton

Chloroplasts

organelles that capture the energy from sunlight and convert it into chemical energy in a process called photosynthesis

Bacteria

single-celled organisms that lack a nucleus; prokaryotes

Gap Junctions

(communicating junctions) provide cytoplasmic channels between adjacent cells

Eukaryotic

A cell characterized by the presence of a nucleus and other membrane-bound organelles. Eukaryotes can be unicellular (protists) or multicellular (fungi, plants and animals).

Endoplasmic Reticulum

A cell structure that forms a maze of passageways in which proteins and other materials are carried from one part of the cell to another.

Cytoplasm

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

Flagella

A long, whip-like filament that helps in cell motility. Many bacteria are flagellated, and sperm are flagellated.

Central Vacuole

A membranous sac in a mature plant cell with diverse roles in reproduction, growth, and development.

Cytoskeleton

A network of fibers that holds the cell together, helps the cell to keep its shape, and aids in movement

Rough ER

A network of interconnected membranous sacs in a eukaryotic cell's cytoplasm; covered with ribosomes that make membrane proteins and secretory proteins.

Endomembrane System

A network of membranes inside and around a eukaryotic cell, related either through direct physical contact or by the transfer of membranous vesicles.

Nucleoid

A non-membrane-bounded region in a prokaryotic cell where the DNA is concentrated.

Nucleus

A part of the cell containing DNA and RNA and responsible for growth and reproduction

Cell Wall

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

Extra-cellular Matrix (ECM)

A substance in which the cells of an animal tissue are embedded; consists of protein and polysaccharides.

Golgi Apparatus

A system of membranes that modifies and packages proteins for export by the cell

Organelles

A tiny cell structure that carries out a specific function within the cell

Plasmodesmata

An open channel in the cell wall of plants through which strands of cytosol connect from adjacent cells

Prokaryotic

An organism whose cells do not have an enclosed nucleus, such as bacteria.

Chromatin

Clusters of DNA, RNA, and proteins in the nucleus of a cell

Peroxisomes

Contain oxidase enzymes that detoxify alcohol, hydrogen peroxide, and other harmful chemicals

The organelle that produces new plasma membrane is called ______________________________________.

ER

The shipping and receiving center of a cell is the organelle called the _____________________________________.

Golgi apparatus

Mitochondria

Powerhouse of the cell, organelle that is the site of ATP (energy) production

________________________________ cells do not have a nucleus or organelles.

Prokaryotes

Cell

The basic unit of structure and function in living things

Cytosol

The semifluid portion of the cytoplasm.

Microtubules

Thick hollow tubes that make up the cilia, flagella, and spindle fibers.

Intermediate Filaments

Threadlike proteins in the cell's cytoskeleton that are roughly twice as thick as microfilaments

Microfilaments

a small rodlike structure, about 4-7 nanometers in diameter, present in numbers in the cytoplasm of many eukaryotic cells.

Plasma Membranes

a thin structure lying inside the cell wall, encloses the cell's cytoplasm

Chromosomes

a threadlike structure of nucleic acids and protein found in the nucleus of most living cells, carrying genetic information in the form of genes.

In terms of function, the most important difference between prokaryotic and eukaryotic cells is.... a.) Eukaryotic cells are larger than prokaryotic cells b.) Eukaryotic cells are compartmentalized, which allows for specialization c.) Eukaryotic cells are much more successful than prokaryotic cells d.) Eukaryotic cells can synthesize proteins but prokaryotic cells cannot e.) Eukaryotic cells lack many of the organelles found in prokaryotes.

b

Which of the following categories best describes the function of the rough endoplasmic reticulum? a.) Information storage b.) Manufacturing c.) Breakdown of complex foods d.) Structural support cells e.) Energy processing

b

What is the functional connection between the nucleolus, nuclear pores, and the nuclear membrane? a.) Membrane of the endoplasmic reticulum is produced in the nucleolus and leaves the nucleus through the nuclear pores b.) The nuclear pores are connections between the nuclear membrane and the endoplasmic reticulum that permit ribosomes to assemble on the surface of the ER c.) Subunits of ribosomes are assembled in the nucleolus and pass through the nuclear membrane via the nuclear pores d.) The nucleolus contains messenger RNA (mRNA - single-stranded copies of sections of DNA), which crosses the nuclear envelope through the nuclear pores

c

Which of the following groups is primarily involved in synthesizing molecules needed by the cell? a.) Smooth ER, ribosomes, vesicles b.) Lysosomes, vesicles, ribosomes c.) Ribosomes, rough ER, smooth ER d.) Rough ER, lysosomes, vesicles e.) Vesicles, rough ER, smooth ER

c

Which of the following macromolecules leave the nucleus of a eukaryotic cell through pores in the nuclear membrane? a.) DNA b.) Amino acids c.) mRNA d.) Phospholipids

c

Lysosomes

cell organelle filled with enzymes needed to break down certain materials in the cell

The organelle that converts C02 and H2 0 into carbohydrates using sunlight is _____________________________.

chloroplasts

The internal structural support for animal cells comes from the ________________________________, whereas, the ________________________________ provides support on the outside of the cell.

cytoskeleton / cell membrane

A substance moving from outside the cell, into the cytosol of a cell, must pass through a.) The nucleus b.) A microtubule c.) The endomembrane system d.) The plasma membrane e.) The rough ER f.) The smooth ER

d

A particular cell has a nucleus and chloroplasts in addition to the fundamental structures required by all cells. Based on this information, this cell could be _______________. a.) Bacteria b.) A cell from the intestinal lining of a cow c.) A yeast (fungus) cell d.) A cell from a pine tree e.) A photosynthetic protist cell or a plant cell

e

Dye injected into a plant cell might be able to enter an adjacent cell through __________________. a.) A gap junction b.) A microtubule c.) A cell wall d.) A tight junction e.) Plasmodesmata f.) Desmosomes

e

Dye injected into an animal cell might be able to enter an adjacent cell through __________________. a.) A gap junction b.) A microtubule c.) A cell wall d.) A tight junction e.) Plasmodesmata f.) Desmosomes

e

Which type of cell is most likely to have the largest number of mitochondria? a.) Photosynthetic cell in the leaves of a tree b.) Nondividing skin cells c.) Bacterial cells that are growing on sugars d.) Dormant yeast cells e.) Muscle cells in the calves of an athlete

e

All Eukaryotic cells have mitochondria that produce glucose. ________

false

Central vacuoles store water and starch in plants. ________

false

Lysosomes and Chloroplasts are found in plant cells. ________

false

Lysosomes break down molecules by dehydration synthesis. ________

false

Organisms belonging to Protista, Fungi, Plantae, and Animalia have a nucleus and double-membrane-bound chloroplasts. ________

false

Plant cells lack a cytoskeleton because they have a rigid cell wall. ________

false

Ribosomes read/translate DNA to form proteins. ________

false

The simplest collection of matter that can be alive is a macromolecule. ________

false

The endomembrane system of a cell is made up of the cell membrane, lysosomes/vacuoles, nuclear membrane, the ER, and the ______________________________________.

golgi apparatus

The cytoskeleton is made of microtubules, microfilaments, and ________________________________________.

intermediate filaments

Plant cells always have the following: a.) Lysosomes b.) Cell walls c.) Nucleus d.) Mitochondria e.) Plasma membrane f.) Chloroplasts g.) Peroxisomes h.) Centrosomes i.) A, B, C, E, F, G j.) B, C, D, E, F, G k.) A, C, E, F, G, H l.) B, C, E, F, G, H m.) All of the above

j

Animal cells always have the following: a.) Lysosomes b.) Cell walls c.) Nucleus d.) Mitochondria e.) Plasma membrane f.) Chloroplasts g.) Peroxisomes h.) Centrosomes i.) A, B, C, E, F, G j.) B, C, D, E, F, G k.) A, C, D, E, G, H l.) B, C, E, F, G, H m.) All of the above

k

In animals, the breakdown of macromolecules happens in the organelles called ____________________________.

lysosomes

The cytoskeleton is made up of different rope-like proteins, the thickest are _______________________________.

microtubules

The organelle that breaks down carbohydrates into C02 , H2 0 and ATP is ___________________________________.

mitocondria

The organelles that produce hydrogen peroxide and then converts it to water are _________________________.

peroxisomes

The channels /pores in cell walls are called _______________________________________.

plasmodesmata

Phagocytosis

process in which extensions of cytoplasm surround and engulf large particles and take them into the cell

Ribosomes

site of protein synthesis

Vesicles

small membrane sacs that specialize in moving products into, out of, and within a cell

Prokaryotes do not have a nucleus, but their DNA is present in an area called the __________________________.

the nucleoid

Eukaryotic cells produce ribosomes in an area of the nucleus called the _______________________________.

the nucleolus

Endosymbiotic Theory

theory that eukaryotic cells formed from a symbiosis among several different prokaryotic organisms

Proteins that span (go all the way through) the cell membrane are called ___________________________________.

transmembrane protiens

Animal and Fungi cells do not contain chloroplasts. ________

true

Cell size is limited by the ratio of surface area to volume. ________

true

Every organism has phospholipids. ________

true

Motor proteins transport vesicles along microtubules. ________

true

Organisms belonging to Bacteria, Archaea, and Eukarya have ribosomes. ________

true

Plant cells contain chloroplasts, but not mitochondria. ________

true

Plants and Fungi have cell walls surrounding each cell. ________

true

Products bound by membrane destined to leave the cell are typically made by rough ER. ________

true

Ribosomes can exist freely (in the cytosol) or bound to the ER. ________

true

The endoplasmic reticulum is attached to the nuclear membrane. ________

true