Cell Biology Overview

Front 1

The smallest unit that scientists agree is alive is the _____.

Back 1

cell

Front 2

The region in a human cell that houses the bulk of the genetic material is the _____.

Back 2

nucleus or nuclear region

Front 3

Most of the cellular machinery in human cells is in the _____.

Back 3

cytoplasm or cytoplasmic
region

Front 4

Cellular interactions with the environment are controlled by which region of the cell?

Back 4

membrane or membraneassociated
region

Front 5

The basic structure of a cell's membrane is a(n) _____ bilayer with associated proteins
that can be either _____ or _____.

Back 5

phospholipid; integral;
peripheral

Front 6

Receptors in the cell's surface tend to be made of _____.

Back 6

protein

Front 7

The molecules that allow cells to join and adhere to one another and or objects are made
of _____.

Back 7

protein

Front 8

When a cell is attached to a substrate, the cell's membrane is protected from ripping by
_____ which pass the external forces from the exterior to the interior of the cell.

Back 8

membrane proteins

Front 9

_____ are membrane junctions which prevent passage of materials between two cells.

Back 9

Tight junctions

Front 10

_____ are membrane junctions which allow force to be passed from cell to cell without
separation of, or damage to, the cellular membranes.

Back 10

Desmosomes

Front 11

_____ are membrane junctions which contain hollow channels within them that allow ions
to pass through from cell to cell.

Back 11

Gap junctions

Front 12

When a molecule moves from an area of high concentration to an area of low
concentration, the process is called _____.

Back 12

diffusion

Front 13

Molecules can passively diffuse through the plasma membrane with the aid of _____
proteins, which form a tunnel that specific molecules can travel, and _____ proteins,
which bind to a molecule and change shape so that un-binding occurs on the opposite
side of the membrane.

Back 13

channel; carrier

Front 14

If a molecule can only pass through a membrane with the assistance of a membrane
protein, but the direction of its travel is controlled only by its concentration, the process is
called _____ diffusion.

Back 14

facilitated

Front 15

When water moves from an area where there is more water to an area where there is
less, the process is called _____.

Back 15

osmosis

Front 16

_____ is the diffusion of water molecules.

Back 16

Osmosis

Front 17

When a cell is surrounded by solution of equivalent solute concentration, the solution is
said to be _____ to the cell, and the net movement of water is _____.

Back 17

isotonic; absent

Front 18

When a cell is surrounded by solution of higher solute concentration, the solution is said to
be _____ to the cell, and the net movement of water is _____.

Back 18

hypertonic; out of the cell

Front 19

When a cell is surrounded by solution of lower solute concentration, the solution is said to
be _____ to the cell, and the net movement of water is _____.

Back 19

hypotonic; into the cell

Front 20

_____ is the passage of liquids and solutes through membranes due to differences in
pressure, a process which is important in the kidney.

Back 20

Filtration

Front 21

When energy is being used to move a solute from low to high areas of concentration, the
process is called _____.

Back 21

active transport

Front 22

The concentration of sodium is highest [outside / inside] the cell, while for potassium, the
reverse is true.

Back 22

outside

Front 23

Sodium and potassium gradients are maintained by an active-transport protein called the
sodium-potassium pump, which moves _____ sodiums out of the cell for every _____
potassium ions brought in.

Back 23

3; 2

Front 24

The energy to operate the sodium-potassium pump comes from the hydrolysis of _____,
which transfers a(n) _____ to the transport protein.

Back 24

ATP; phosphate bond or highenergy
phosphate bond

Front 25

In _____, interactions between vesicle proteins and plasma membrane proteins cause a
vesicle to merge with the plasma membrane and discharge its contents to the cell's
exterior.

Back 25

exocytosis

Front 26

In _____, clathrin-coated regions of the cell's exterior invaginate and form vesicles which
bring a portion of the extracellular material into the cell.

Back 26

clathrin-mediated endocytosis

Front 27

When a vesicle is formed on one side of the cell to endocytose extracellular material, and
actually traverses the cell to leave on the other side, the process is called _____. (This
process is important in digestion.)

Back 27

transcytosis

Front 28

Endocytosis, exocytosis, and transcytosis are all examples of _____ transport.

Back 28

active

Front 29

A difference in the number of positive and negative charges on the two sides of a
membrane is referred to as the _____.

Back 29

membrane potential

Front 30

The two factors that act in opposite ways to stabilize the resting membrane potential are
_____ and _____.

Back 30

concentration gradients (or
diffusion) and electrostatic
attraction

Front 31

The two major ions responsible for the membrane potential in human cells are _____ and
_____.

Back 31

sodium; potassium

Front 32

The glycocalyx is composed of _____ molecules (a class of macromolecule) attached to
proteins and lipids on the cell surface.

Back 32

carbohydrate

Front 33

Cells sense contact with other cells and with surfaces, and adhere to substrates and other
cells, largely via the use of carbohydrate-rich macromolecules in the cell membrane which
together compose the _____.

Back 33

glycocalyx

Front 34

The three major signal types recognized by membrane receptors are _____ signals,
_____ signals, and _____.

Back 34

chemical, electrical, contact

Front 35

A common function of all _____ is to transmit an external event, as a signal, into the cell
to allow the cell to respond.

Back 35

membrane receptors

Front 36

The entire region between the cellular nucleus and the membrane is called the _____, the
liquid portion is called the _____, and the membrane-enclosed compartments in which
specific functions are localized are called _____.

Back 36

cytoplasm; cytosol; organelles

Front 37

f a particle in the cell's cytoplasm can be seen with light microscopy, it is called a(n)
_____.

Back 37

inclusion

Front 38

Mitochondria have _____ (how many?) membranes, each of which is a bilayer.

Back 38

two

Front 39

The innermost membrane of mitochondria is folded, forming wrinkles called _____.

Back 39

cristae

Front 40

The major (not only) function of mitochondria is to completely oxidize fuels and to capture
the energy in a molecule called _____.

Back 40

ATP

Front 41

_____ are huge macromolecules composed of RNA and protein, whose function is to
synthesize protein.

Back 41

Ribosomes

Front 42

Cytosolic proteins are made by _____ ribosomes, while proteins destined for export, or
use in membrane, are made by _____ ribosomes.

Back 42

free; membrane bound (or ER
bound)

Front 43

The rough endoplasmic reticulum is distinguished by the presence of _____ on its
surface, and is responsible for making integral membrane proteins, secreted proteins, and
phospholipids.

Back 43

ribosomes

Front 44

Ribosomes become bound to the membrane of the rough ER after they have started
making protein due to the presence of a(n) _____ on the newly made protein which binds
to receptors called SRPs (Signal Recognition Particles) on the ER surface.

Back 44

signal sequence

Front 45

The function of the _____ ER varies greatly from cell type to cell type, and can include
lipid metabolism, steroid synthesis, calcium storage and release, and others.

Back 45

smooth

Front 46

Proteins leaving the rough ER are transported to the _____ for modification, packaging,
and transport to the appropriate location.

Back 46

Golgi apparatus

Front 47

The series of organelles that are able to exchange membrane components with one
another are collectively known as the _____.

Back 47

endomembrane system

Front 48

The organelles within the cell whose main functions are digestion and hydrolysis are the
_____.

Back 48

lysosomes

Front 49

The organelles which isolate hazardous chemical reactions within the cell, especially
those producing free radicals, are called _____.

Back 49

peroxisomes

Front 50

The three principle components of the cytoskeleton are _____, _____, and _____.

Back 50

microfilaments, intermediate
filaments, and microtubules

Front 51

The primary functions of _____ are to brace and strengthen the cell's surface and to
attach to cellular adhesion molecules which allow binding to substrates and other cells.
They also function in endocytosis and exocytosis.

Back 51

microfilaments

Front 52

The semi-permanent structural framework of the cell, which transmit force from one point
in the membrane to others, allowing cells to spread a stretching force across a wide
region and to other cells, are the _____.

Back 52

intermediate filaments

Front 53

The dynamic, hollow tubes which help to determine the overall shape of the cell and along
which organelles move as if on a conveyor belt are the _____.

Back 53

microtubules

Front 54

The molecules which use energy from ATP to move organelles along certain components
of the cytoskeleton are called _____.

Back 54

motor molecules

Front 55

The structures that organize and generate the microtubules for the mitotic spindle during
mitosis and for cilia and flagella are called _____.

Back 55

centrioles

Front 56

Short, cellular projections that allow the cell to move through their environment, or for
human cells, to move fluid across their surface, are called _____.

Back 56

cilia

Front 57

The cytoskeletal components that give cilia their mobility and structural strength are _____.

Back 57

microtubules

Front 58

The primary difference between cilia and flagella is _____.

Back 58

length

Front 59

The nuclear envelope consists of _____ (how many?) separate membrane bilayers?

Back 59

two

Front 60

The outer membrane of the nuclear envelope is continuous with the _____.

Back 60

rough E.R.

Front 61

The function of the _____ is to regulate which materials enter or leave the nucleus.

Back 61

nuclear membrane

Front 62

Large molecules are transported into or out of the nucleus through _____.

Back 62

nuclear pores

Front 63

Ribosomal RNA is produced in _____.

Back 63

nucleoli

Front 64

DNA wrapped around histones within the nucleus is called _____ because it could take up
dyes and showed as a colored substance when a microscope was used.

Back 64

chromatin

Front 65

The cell cycle can be divided into two major phases, _____ and _____.

Back 65

interphase; mitotic or mitosis

Front 66

Interphase can be divided into three groups of events, _____, _____, and _____.

Back 66

G1 (or gap 1); S (or synthesis);
G2 (or gap 2)

Front 67

DNA is made during the _____ phase of the cell cycle (be as specific as possible).

Back 67

S or Synthesis

Front 68

Cells that have permanently stopped dividing enter a phase of the cell cycle known as
_____.

Back 68

G0

Front 69

Cell growth and preparation for cell division occur during the _____ and _____ phases,
respectively.

Back 69

G1; G2

Front 70

Replication or division of the nucleus is called _____; once there are two nuclei, the cell
itself may divide in a process called _____.

Back 70

mitosis; cytokinesis

Front 71

Mitosis consists of four phases. In order, they are _____, _____, _____, and _____.

Back 71

prophase; metaphase;
anaphase; telophase

Front 72

During _____, the nuclear envelope dissolves and the chromatin condenses.

Back 72

prophase

Front 73

During _____, the individual chromosomes line up in the middle of the cell.

Back 73

metaphase

Front 74

In _____, the sister chromatids separate.

Back 74

anaphase

Front 75

In _____, a new nuclear envelope forms.

Back 75

telophase

Front 76

DNA is made by enzymes called _____.

Back 76

DNA polymerases

Front 77

During DNA synthesis, new nucleotides can only be added to the _____ end of the DNA.

Back 77

3'

Front 78

The structure of DNA is anti-parallel, meaning that the strands are _____.

Back 78

parallel, but pointed in opposite
directions

Front 79

The _____ strand of DNA is made discontinuously (in small pieces).

Back 79

lagging

Front 80

DNA polymerases require a(n) _____, which in the cell is either a pre-existing piece of
DNA, or a newly made piece of RNA.

Back 80

primer

Front 81

When RNA is removed from the lagging strand during DNA synthesis, it is replaced by
DNA everywhere except at the _____ end of the strand. It cannot be replaced there,
because there is no _____.

Back 81

5'; primer

Front 82

A hereditary nucleic acid sequence which contains the information needed to make a
cellular component is called a(n) _____.

Back 82

gene

Front 83

Using a codon table, translate <AUGGCUUUU> into the correct amino acid. (Note:
understand the principle. The exact sequence will not be the same on a test.)

Back 83

methionine-alaninephenylalanine

Front 84

In humans, _____ is the chemical which contains the original sequence information
encoding proteins and other cellular components, and which is the 'master copy' that is
passed on to future generations.

Back 84

DNA

Front 85

In humans, _____ is a disposable copy of the nucleic acid sequence which contains the
information encoding proteins and other cellular components. It is used by the ribosomes
in the cytoplasm to create a protein with the correct amino acid sequence.

Back 85

mRNA

Front 86

_____ is a form of RNA that carries amino acids to the ribosome during protein synthesis.

Back 86

tRNA

Front 87

_____ is a form of RNA that is a physical component of the ribosome.

Back 87

rRNA

Front 88

During _____, the sequence of the DNA is copied into RNA. During _____, the ribosome
uses the nucleotide sequence to create a protein with the correct amino acid sequence.

Back 88

transcription; translation

Front 89

Codons are found in _____ RNA, while anticodons are found in _____ RNA.

Back 89

messenger or m; transfer or t

Front 90

Translation occurs in which part of the cell?

Back 90

Cytoplasm.

Front 91

Non-functional organelles are degraded by _____.

Back 91

lysosomes

Front 92

Proteins which are no longer functional are marked for degradation by the addition of
_____.

Back 92

ubiquitin

Front 93

The _____ is an organized, extracellular mesh of varying density in which cells are found.

Back 93

extracellular matrix

Front 94

At the DNA level, the difference between a liver cell and a brain cell, is that they _____,
although they have the same _____.

Back 94

have different genes active;
DNA

Front 95

The development of specific and distinctive features in a cell (example, when a cell
becomes a liver or a brain cell) is called _____.

Back 95

differentiation or cell
differentiation

Front 96

In organisms that age, repair of damage is _____.

Back 96

imperfect

Front 97

In organisms that _____, unrepaired, damaged parts are not replaced.

Back 97

age

Front 98

In organisms that _____, life processes which have short term benefits but which have
negative effects in the long term are allowed to occur.

Back 98

age

Front 99

One way to delay the effects of aging on some organ systems (those few for which this is
possible) is to engage in activities, such as weightlifting, which induce _____.

Back 99

repair