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