Module 2 Flashcards
Basic functional unit of life
The Cell
o aka body cells
o have two copies of the genome
(except mature RBC’s) and are said
to be diploid (2n)
Somatic cell
o Aka sex cells (sperm and egg cells)
o have one copy of the genome and
are haploid (1n or n)
Germ cells
o Give rise to differentiated cells and to other stem cells (self-renewal)
o Diploid
Stem cells
Tight cell layers form linings that
protect, secrete, absorb, and excrete
Epithelium
transmit information as electrochemical impulses that coordinate movement and also sense and respond to
environmental stimuli; neuroglia support and
nourish neurons
Nervous Neurons
A variety of cell types
and surrounding materials protect, support, bind to cells, and fill spaces throughout the body; include cartilage, bone, blood, and fat
Connective tissues
provide energy and contribute to cell structure
Carbohydrates
form the contractile fibers, clot formation and enzymatic reaction
Proteins
basis of some hormones, provide insulation, energy storage and formation of membranes
Lipids
translate information from past generations to new cells that give its characteristics. They are the most important
macromolecules to the study of genetics
Nucleic Acids
carry out the activities of life in the cell; divide the labor by partitioning off certain areas or serving specific functions
Organelles
The most prominent organelle of most cells
Contains the DNA within the cell
Nucleus
surrounds the nucleus
Nuclear envelope
biochemicals can exit or enter the nucleus through them
Nuclear pores
mechanical support; holds the nuclear pores in place
Nuclear lamina
“little nucleus”; darkened area
inside the nucleus (when viewed under the
microscope); site of ribosome synthesis
Nucleolus
the fluid in the nucleus
Nucleoplasm
Remainder of the cell between the nucleus
and the cell membrane
Cytoplasm
the aqueous component of the
cytoplasm of a cell, within which various
organelles and particles are suspended
Cytosol
Quality control center of the cell
Winds from the nuclear envelope outward to
the plasma membrane, forming a vast tubular
network that transports molecules from one
part of a cell to another
Endoplasmic Reticulum (ER)
o Studded with ribosomes
o Starting point of protein synthesis
Rough ER
o Fewer ribosomes
o Lipid synthesis
Smooth ER
lipid made, membrane bound, saclike
organelles
pinch off from the tubular endings of the ER
to form sacs for transport of substances
within the cell
Vesicles
column of four to six interconnected flat,
membrane-enclosed sacs
Golgi apparatus
What are the formulas and products for sugar synthesis
o Sugar + Lipid = Glycolipid
o Sugar + Protein = Glycoprotein
Vesicles that bud from one cell and then
travel to, merge with, and empty their
contents into other cells (the opposite is true
for endosomes)
Exosomes
“suicide sac”
membrane- bound sacs that contain
enzymes able to degrade bacteria, worn- out
organelles and others such as cholesterol
Lysosomes
“eating self”- ability of the cell to dispose of its own remnants
Autophagy
Sacs with single outer membrane, filled with
enzymes
catalyze reaction that
breakdown certain lipids and rare
biochemical, synthesize bile acids used in fat
digestion and detoxify compound that result
from exposure to oxygen free radicals
Peroxisomes
“Powerhouse of the Cell”
provide energy by breaking the chemical
bonds that hold together the nutrient
molecules in food
Mitochondrion
– source of energy of the cell
Adenosine Triphosphate (ATP)
– hold the enzymes that catalyze the biochemical reactions that release energy
Cristae
meshwork of protein rods and tubules that
serves as the cell’s architecture, positioning
organelles and providing the overall 3-
dimensional shapes
Cytoskeleton
o Made up of tubulin
o Cellular organization, communication between cells
o form hairlike structures called cilia, that propels substances
Microtubules
o Made up of actin
o narrower than microtubules
o enable cells to withstand stretching and compression, and help anchor one cell to another.
Microfilaments
o composed of different types of proteins
o have diameters intermediate between those of microtubules and microfilaments
Intermediate Filaments
Completely surrounds the cell
It is a double layer (bilayer) of molecules
called phospholipids
Monitors the movements of molecules in and
out of the cell
Plasma Membrane
The phosphate end of a phospholipid is
attracted to water, and thus is __________
hydrophilic (“water loving”)
The other end, which consists of two chains
of fatty acids, moves away from water, and is
therefore
hydrophobic (“water fearing”)
are embedded in the phospholipid
bilayer of biological membranes.
Proteins
what kind of transport does not require energy
Passive Membrane Transport
what kind of transport requires energy, usually in the form of Adenosine Triphosphate (ATP)
Active Membrane Transport
A series of events called the _______ describes the
sequence of activities as a cell prepares for and
undergoes division.
cell cycle
Cell continues the basic biochemical
functions of life, while also replicating its DNA
and some organelles.
Interphase
o cell resumes synthesis of proteins,
lipids, and carbohydrates
o it is the period of the cell cycle that
varies the most in duration among
different cell types
G1 phase
– a cell can exit the cell cycle at
G1 to enter a quiet phase
G0
o synthesis of biochemicals for
microtubule formation
G2 phase
o Synthesis phase
o DNA replication
S phase
Each chromosome consists of two
copies of the genome joined at an
area called the
centromere
Microtubules form structures called
centrioles that join with other
proteins and are oriented at right
angles to each other, forming paired,
oblong structures called ___________
centrosomes
Microtubules form structures called __________ that join with other proteins and are oriented at right
angles to each other, forming paired,
oblong structures called
centrosomes
centrioles
Long strands of chromosomal material in replicated
chromosomes
chromatids
attached at a centromere
sister chromatids
DNA coils tightly
Chromosomes condense
Microtubules assemble
Nuclear membrane breaks down
Nucleolus is no longer visible.
Prophase
What are the four stages of mitosis
Prophase
Metaphase
Anaphase
Telophase
Chromosomes attach to the spindle at their
centromeres and align along the center of the
cell, which is called the equator
Metaphase
Centromeres part
Chromatid from each pair move to opposite
ends of the cell.
Anaphase
Mitotic spindle falls apart
Nucleoli and the membranes around the
nuclei re-form at each end of the elongated
cell
Telophase
microfilament band contracts
like a drawstring, separating the newly formed cells. Apportions contents to daughter cells.
Cytokinesis
The cell cycle is tightly controlled and regulated
at several ___________
checkpoints
temporarily pauses the cell cycle while special proteins
repair damaged DNA.
DNA Damage Checkpoints
turns on as mitosis begins. During this checkpoint, proteins called survivins override signals telling the
cell to die, so that mitosis (division) rather
than apoptosis (death) occurs.
“Apoptosis checkpoint”
oversees construction of the spindle and the binding of
chromosomes to it
“Spindle assembly checkpoint”
a cellular clock that limits the number of divisions. Its length determines how many more times mitosis will
occur.
Telomere (chromosome tip)
Some cells (eggs, sperm, bone marrow cells, cancer cells ) have ______ that keeps chromosome tips long
telomerase
within cells ______ and ______ activate genes whose products carry out mitosis
kinases and cyclins
Disruption of the balance between cell division
and cell death can lead to ____
cancer
a form of cell death associated with inflammation and damage, rather
than an orderly, contained destruction
Necrosis
Gametes form from special cells, called germline
cells, in a type of cell division called _________
meiosis
if gametes have only ONE of each type of
chromosome (23 chromosomes) they are considered______
haploid
if gametes have TWO copies of each
chromosome type (23 pairs of
chromosomes for a total of 46
chromosomes) they are considered ______
diploid
- halves the chromosome number (46 divided by 2 = 23)
Meiosis I
mitotically divides each of the two cells, yielding four haploid cells.
Meiosis II
Chromosomes condense
Prophase I
homologous pairs of chromosomes line up next to one another in an event called _______
synapsis
Homologs exchange parts, in a process known as ______
crossing over
Homologs align down randomly at the center
of the cell.
Metaphase I
the fate of a gene on one chromosome is not influenced by a gene on a different chromosome
independent assortment
Homologs separate
Anaphase I
Homologs move to opposite poles. Unlike in mitosis, the centromeres of each homolog in meiosis I remain together
Telophase I
During a second interphase, chromosomes unfold
into thin threads. Proteins are manufactured, but DNA is not replicated a second time
Meiosis II
Chromosomes are again condensed and visible.
Prophase II
Replicated chromosomes align down the center
of the cell.
Metaphase II
The centromeres part, and the newly formed chromosomes, each now in the unreplicated form, move to opposite poles.
Anaphase II
Nuclear envelopes form around the four nuclei,
which then separate into individual cells.
Telophase II
may enable a population to survive an environmental
challenge.
genetic diversity
