Unit 2 Flashcards
What happens during G0? What comes after it?
Normal specialized cell functions happen during G0 phase. When mitogens are introduced the cell enters interphase at the G1 phase.
What happens during G1? What stages come before and after it?
G1 is a period of cell growth, protein synthesis, and organelle duplication/ production. G1 is a stage of interphase with G0 coming before and the S stage coming after.
What happens during the S stage? What stages come before and after it?
The S stage is the period which DNA is replicated (makes a copy of every chromosome - DNA remains in the chromatin state), and histones are synthesized. It is a part of interphase with the G1 stage coming before and the G2 stage coming after.
What happens during the G2 stage? Which states come before and after?
G2 is a period of more growth, protein synthesis, and DNA begins to condense. S stage comes before and prophase comes after.
The largest portion of the cell cycle, when a parental cell is growing in preparation for division, synthesizing all necessary proteins for that task, and duplicating all of its DNA molecules, is called _______.
interphase
A region of DNA that contains the information needed to make one or more functional proteins is called a ______.
gene
Regulatory proteins that bind to DNA at the promoter region and either activate or inactivate the expression of a gene are called _____.
transcription factors
This process occurs when the DNA base sequence is used to make a complementary piece of RNA, specifically called pre-mRNA.
transcription
In what part of the cell is a section of DNA copied into RNA?
nucleus
This enzyme separates the two strands of the DNA double-helix at a specific gene and synthesizes a complementary strand of RNA.
RNA polymerase
This is the specific kind of RNA that is complementary to a gene coded in DNA and is ultimately read by ribosomes to create the protein.
mRNA
______ are noncoding segments of an immature or pre-mRNA molecule that are removed during alternative splicing (or mRNA processing) to convert pre-mRNA into mature mRNA.
introns
______ is the extracellular fluid of your erythrocytes, leukocytes, and
thrombocytes.
Plasma
______ is the extracellular fluid that surrounds body tissue cells.
Interstitial fluid
______ is the fluid inside body cells where the nucleus, organelles, and
inclusions are suspended.
Intracellular fluid
_______ is defined as the passive movement of molecules from an
area of higher concentration to an area of lower concentration of
those molecules.
Diffusion
There is a very specific term for the passive movement of water across the plasma membrane to maintain osmotic equilibrium. That term is _____.
osmosis
There are two types of membrane transporters. This sub-type is a
water-filled passageway that directly links the extracellular and
intracellular compartments. These membrane transporters also ONLY
allow for passive transport of ions.
Channel proteins
This sub-type of membrane transporter binds to its substrate(s) on one side of the plasma membrane, changes conformation, and transports it/them through to the other side, but never forms a direct connection between the intracellular and extracellular compartments. These membrane transporters can also do either passive or active transport.
carrier proteins
If molecules move through the plasma membrane via membrane transporters, move down their concentration gradient, and net transport stops when the concentrations are equal on both sides of the
membrane, the process is specifically known as _____________.
Facilitated diffusion
During alternative splicing or mRNA processing, some sections of the pre-mRNA molecule are kept and spliced together to form the mature mRNA molecule. These sections that are kept and spliced together are called ______.
exons
If molecules move through the plasma membrane via membrane transporters, move against their concentration gradient, and ATP is needed as an energy source, this process is known as ___________.
Active transport
This is the name of the process where mature mRNA directs the assembly of amino acids into a polypeptide or protein.
translation
_________ channels or pores spend most of their time with their gate
open, allowing ions to move back and forth across the membrane
without regulation.
Open
________ channels spend most of their time closed, but can be opened under specific conditions then they allow the movement of ions across the plasma membrane.
Gated
These channels will change conformation and open when the electrical state of the cell reaches a specific level.
Voltage-gated
Where a mature mRNA molecule is read to create a new protein chain, happens at these intracellular inclusions.
ribosomes
These channels must bind an intracellular or extracellular signal molecule to change conformation and become open.
Chemically-gated
A triplet of mature mRNA bases that codes for a specific amino acid is called a ______.
codon
If a carrier protein moves two or more types of solutes in opposite directions, it is specifically called an ________ carrier.
Antiport
_____ is the molecule that delivers a specific amino acid to the ribosome during translation so it can be attached to the growing polypeptide or protein.
tRNA
If a carrier protein moves two or more types of solutes in the same
direction, it is specifically called a ______ carrier.
Symport
If a membrane channel opens, Na+ ions would flow (into or out of) the
cell.
Into
If a membrane channel opens, K+ ions would flow (into or out of) the
cell.
Out of
A triplet of nucleotide bases called a(n) __________ that binds to a complementary trio of bases on the mature mRNA molecule.
anticodon
If a membrane channel opens, Cl- ions would flow (into or out of) the
cell.
Into
If a membrane channel opens, Ca2+ ions would flow (into or out of) the
cell.
Into
Proteins are not usually in their final or mature form when they are first produced. They typically must undergo ________ within the lumen of the rough endoplasmic reticulum, where they fold into complex shapes, may be split by enzymes into smaller peptides, or have various chemical groups added to them.
post-translational modification
mRNA does not last forever. Cells need to have control over protein synthesis after all. When mRNA is no longer needed, it is broken down by a class of enzymes called ____.
ribonucleases
The smaller portion of cell cycle, when the duplicated parental chromosomes are separated and passed to the new daughter cells, and the cytoplasm of the parental cells divides, is called ______.
mitosis
When human body cells divide out of control, a disease broadly referred to as _____ can arise, where groups of these defective cells accumulate into a mass or migrate throughout the body, ultimately interfering with normal physiological mechanisms.
cancer
The electrical gradient (difference) between the extracellular fluid and the intracellular fluid is known as the ____________.
Membrane potential
During this sub-phase of Interphase, a cell will duplicate all its DNA molecules (chromosomes) so that each daughter cell gets a full complement of genetic instructions.
S phase
For nerve and muscle cells, the inside of the cell is more _________
charged relative to the outside.
negatively
There are points in the cell cycle called _______ where the cell determines if its DNA is healthy and if it has enough resources to divide successfully.
checkpoints
If Cl- ions diffuse through an ion channel, the inside of the cell becomes
__________, meaning it becomes more negatively charged than
before.
Hyperpolarized
If Na+ ions diffuse through an ion channel, the inside of the cell
becomes __________, meaning it becomes more positively charged
than before.
Depolarized
When a cell determines that it cannot fix an error in its DNA and cannot complete its cell cycle successfully, it will usually undergo a process called _______ where it will self-destruct.
Apoptosis