Biology- The Living World Ch.4
List the correct sequence of the receptor-mediated endocytosis process.
1. molecules bind to specific membrane receptors 2. plasma membrane invaginates and the coated pit deepens 3. pit closes over to form internal vesicle
A dense network of protein fibers called the________ provides a framework within the cell that supports the cell interior and anchors organelles.
cytoskeleton
The net movement of molecules down a concentration gradient toward regions of lower concentration as a result of random motion is called ______.
diffusion
Select all of the functions of the cell nucleus.
directs cell activity stores hereditary information
When diffusion slows to a halt, molecules continue to move, but the relative concentrations of the two regions no longer change. This is state called ______.
dynamic equilibrium
The _____ motor protein moves inward toward the cell's center, dragging a vesicle or cell component with it as it travels along a microtubule.
dynein
Open ion channels with gates that swing open or shut in response to ________ charge play an essential role in signaling by the nervous system.
electrical
Open ion channels with gates that swing open or shut in response to _______charge play an essential role in signaling by the nervous system.
electrical
The process by which the plasma membrane engulfs either a particle or liquid and forms a vesicle around it is called ______.
endocytosis
In eukaryotes the nucleus is the cell's control center and contains the ______.
DNA
_______ bodies are flattened stacks of membranes that serve as the cell's post office by packaging and distributing materials.
Golgi
Select all of the organelles found in a typical eukaryotic cell.
Golgi complex mitochondria
How do modern light microscopes allow us to visualize cells?
They have two lenses and a variety of correcting lenses that increase magnification and clarity.
Select all of the cell-like organelles that have their own DNA.
chloroplasts mitochondria
In eukaryotes DNA is organized into _______ with associated proteins.
chromosomes
The DNA of a eukaryotic cell is divided into several _________ , which are segments of DNA associated with proteins.
chromosomes
If flagella are numerous and organized in dense rows, they are called
cilia
What organelle is bounded by two membranes and is the site of photosynthesis?
chloroplast
All photosynthesis in plants and algae takes place within a bacteria-like organelle called the _________ .
chloroplast or chloroplasts
What system of internal membranes within a eukaryotic cell functions in protein, carbohydrate, and lipid synthesis?
endoplasmic reticulum
Select all of the characteristics of a eukaryotic cell.
complex interior organization of organelles. larger than a prokaryotic cell. interior scaffold of protein fibers. nucleus.
Microscopes that magnify in stages using several lenses are called _____ light microscopes
compound
Select all of the characteristics of a peroxisome.
contain two sets of enzymes spherical organelles that contain protein detoxifies various potentially harmful molecules
What are the ways in which an animal cell moves?
crawling or swimming
Select all of the parts of mitochondria.
cristae intermembrane space matrix
All cells contain _______ and are surrounded by a plasma ________
cytoplasm membrane
Select the two macromolecules that make up the plasma membrane.
lipids proteins
What organelle contains a concentrated mix of powerful enzymes that are used to break down and recycle macromolecules and worn-out cell components?
lysosome
Select all of the examples of serious human diseases that result when the endomembrane system does not work as it should
lysosome storage disorders Pompe's disease Tay Sachs disease inclusion-cell disease
Select the two compartments of the mitochondrion.
matrix intermembrane space
Eukaryotes are distinguished from prokaryotes by ______.
membrane-bound organelles a nucleus that contains the DNA
Cell-like organelles that have their own DNA are
mitochondria and chloroplasts.
Select all of the organelles found in animal cells.
mitochondrion endoplasmic reticulum centrioles
Diffusion can be defined as the
net movement of molecules down a concentration gradient toward regions of lower concentration.
The nucleus is contained within a membrane called the ______.
nuclear envelope
Select all of the characteristics of centrioles.
occur in pairs usually located at right angles to one another found near the nuclear envelope
Ions and polar molecules can only pass across the lipid core of membranes by passing through protein channels that bridge the bilayer. The simplest of these channels are called
open channels.
Because of water's biological importance its diffusion down its concentration gradient is specifically referred to as
osmosis
Water diffuses across a cell membrane down its concentration gradient in a process called ______.
osmosis
Spherical organelles called ______ contain enzymes that detoxify harmful molecules and may also contain a large crystal structure composed of protein.
peroxisomes
If the material a cell takes in during endocytosis is a discrete particle, such as a bacterium, the process is called ______.
phagocytosis
A _________ is a modified fat molecule made up of a polar head and two nonpolar tails attached to it.
phospholipid
Some prokaryotic cells have _____, which are short flagella that help organisms attach to appropriate substrates.
pili
When a cell forms vesicles to take in liquid material or substances dissolved in a liquid, it does so through a process called
pinocytosis.
Match the organism on the left with the composition of its cell wall on the right.
plants <----> cellulose fungi <----> chitin
Select the two common structures of all cells.
plasma membrane cytoplasm
Select all the structural characteristics of a phospholipid molecule.
polar head with two nonpolar tails attached to it. modified fat molecules.
Select all of the examples of human cells that utilize flagella or cilia.
tracheal cells sperm
Membrane proteins that provide passageways through the plasma membrane for ions and polar molecules are called ______.
transmembrane proteins
Select all the types of microscopes that are capable of resolving objects only 0.2 nanometers apart.
transmission electron microscope scanning electron microscope
Active transport requires ______.
transport proteins energy
Plant cells contain special membrane-bound storage compartments called
vacuoles.
The idea that all organisms are composed of cells is called the ______.
cell theory
What is the function of ribosomes?
synthesize proteins
How does an organism composed of relatively small cells have an advantage over one made of larger cells?
A small cell can more efficiently direct synthesis of certain enzymes.
Select all the reasons why most cells are so small.
As cells grow larger, they have far less surface available to service each unit of volume. Larger cells do not function efficiently.
______ microscopes magnify in states and can resolve structures that are separated by more than 200 nanometers.
Compound
_______ pressure refers to the pressure of the cytoplasm pushing out against the cell membrane.
Hydrostatic
How do cells of many organisms maintain osmotic balance? Select all that apply.
Many cells have cell walls to stiffen their exteriors resisting swelling due to osmotic pressure. Animals cells have fluids with many polar molecules bathing the cells, making them isotonic.
How do peroxisomes detoxify potentially harmful molecules within the cell?
Peroxisomes use molecular oxygen to remove hydrogen atoms from specific molecules.
In the lysosome storage disorder called _____ disease, lysosomes lack an enzyme necessary to digest glycogen.
Pompe's
Why are lysosomes often referred to as the "recycling centers" of the cell?
The enzymes within the lysosome break down failing organelles and other structures within the cell.
Endocytosis is the process in which ______.
a cell extends its plasma membrane outward toward food particles and engulfs them
Select the four components required for long-distance intracellular transport.
a vesicle or organelle that is to be transported a motor molecule microtubules on which the vesicle will travel connector molecules that connect the vesicle to the motor molecule
The arrangement of _______ filaments within the cell cytoplasm allows cells to crawl.
actin
What filament within the cytoplasm allows cells to crawl and change shape?
actin
The transport of substances across the plasma membrane using carrier proteins that require energy is called ______.
active transport
The cell theory states that ______.
all living things are composed of cells
Select all of the functions of the cytoskeleton.
anchors organelles to fixed locations within the cell's interior provides a framework that supports the shape of the cell
Match the component of the extracellular matrix on the left with its role on the right. fibronectin glycoproteins collagen integrins
attaches the ECM to the plasma membrane forms the ECM form a protective layer over the cell surface an integral part of the plasma membrane that extends into the cytoplasm and attach to the cytoskeleton
A eukaryotic flagellum arises from a microtubular structure called a
basal body.
Membrane proteins that act as markers to identify types of cells are called ______.
cell surface proteins
Select all of the following that describe the sodium-potassium pump.
energy for this operation is derived from ATP expends energy to actively pump sodium and potassium ions across the membrane most important active transport protein energy changes the shape of the protein carrier, allowing ions to be transported in opposite directions
The surface of the nucleus is bounded by a double membrane called the nuclear ______.
envelope
What cells contain a true nucleus?
eukaryotic
What type of cell is characterized by a complex interior organization that includes various organelles and a defined nucleus?
eukaryotic
The type of diffusion that occurs with the use of a special carrier protein which binds only to certain kinds of molecules is called _____ diffusion.
facilitated
The membrane transport mechanism that involves special carrier proteins that move substances from regions of high concentration to regions of low concentration is called ______.
facilitated diffusion
Select all of the components of the extracellular matrix.
fibronectin elastin proteoglycans collagen
_______ are long, threadlike structures on some prokaryotic cells that rotate and allow the cells to move.
flagella or flagellum
Some prokaryotes possess a ______, a long, whiplike tail used to propel them through a medium.
flagellum
Organelles called Golgi bodies are ______.
flattened stacks of membranes
Animal cells secrete an elaborate mixture of ________ into the space around them, forming the extracellular matrix (ECM).
glycoproteins or proteins
The difference in the number of polar and charged molecules and ions on either side of a plasma membrane is called a concentration
gradient
Polar and charged molecules and ions often have a different concentration on one side of the membrane than on the other. This difference in concentration is called the concentration
gradient.
Diffusion rate is most rapid when
gradients are steep.
How do plant cells resist hydrostatic pressure?
having a cell wall
Select all the functions of pili in prokaryotic cells
help the prokaryotic cell attach to appropriate substrates. aid in the exchange of genetic information between cells.
What is the term that describes the pressure of cytoplasm pushing out against the cell membrane?
hydrostatic pressure
Prokaryotes ______.
include the domains Bacteria and Archaea. lack a nucleus.
How are sodium and potassium ions moved across the membrane? Select all that apply.
potassium ions are transported into the cell by the Na-K pump ATP changes the shape of the protein carrier sodium and potassium ions move against their concentration gradients
Match the structure of the plant cell wall with its correct description.
primary cell wall <----> laid down when the cell is growing middle lamella <----> glues adjacent cells together secondary cell wall <----> strong wall deposited inside the primary walls
Bacteria and archaea are two types of organisms consisting of simple cells called ______ cells.
prokaryotic
Ribosomes are the site of ________ synthesis and may occur freely in the cytoplasm or attached to the rough endoplasmic reticulum.
protein
The plasma membrane is made up of ______.
proteins and lipids
Hydrostatic pressure is caused by the cytoplasm
pushing out against the cell membrane.
Specific molecules are often transported into eukaryotic cells by first binding to specific receptors in the plasma membrane. This means of transport is called
receptor-mediated endocytosis.
Cell structures called _______ are composed of rRNA and proteins and are the sites of protein synthesis.
ribosomes
What type of microscope can produce a three-dimensional image of a specimen, with the resolution power of 0.2 nanometers?
scanning electron microscope
Cells have special proteins within their membrane that allow them to control the movement of substances across the membrane. This characteristic of cell membranes is called ______.
selective permeability
The plasma membrane's ability to admit some substances and not others is referred to as _______ _______ . It is a cell's most important property, determining what it is and how it functions.
selective permeable or selectively permeability
List all of the ways in which animal cells move.
some swim with flagella some crawl some swim with cilia
A eukaryotic cell is characterized by ______.
specialized organelles and a distinct nucleus
What human cell uses flagella to swim?
sperm
The main function of the central vacuole of plant cells is
storage.
What is the function of the endoplasmic reticulum?
synthesis and transport of proteins and lipids
