A&P Chap 4
Put the steps of translation into the proper order.
1. Ribosomal subunits bind the mRNA and a tRNA 2. Protein synthesis begins with the amino acid methoinine 3. Anticodons and codons are paired; amino acids are joined 4. A stop codon is read 5. Ribosomal subunits separate releasing the protein
The sodium-potassium exchange pump transports ________ (number) sodium ions out of the cell for every _________ (number) potassium ions it transports into the cell.
3, 2
Primary active transport uses phosphate from the breakdown of _________ to phosphorylate the membrane transport pump resulting in the change in a _____________ conformation (shape) and the subsequent movement of a solute across a membrane.
ATP, protein's
Exocytosis is a means by which cells release substances to the outside. This process requires the cell to expend energy in the form of _____________. Typically the secretion is packaged into __________ which fuse with the __________ membrane prior to release.
ATP, vesicles, plasma
Match DNA structures:
Chromatin: finely filamented mass of DNA and proteins Chromosomes: become visible only when the cell is dividing Nucleosome: DNA double helix wound around a cluster of histones
Match the function of the plasma membrane with its mechanism of action.
Communication: contains receptors that recognize and respond to molecular signals Intercellular connection: junctions form between neighboring cells Physical barrier: phospholipid bilayer separates substances inside and outside the cell Selective permeability: regulates entry and exit of ions, nutrients, and waste molecules through the membrane
All cells are able to undergo cell division and make more cells of all types.
False
The steeper the concentration gradient of a solute, the lower the osmotic pressure.
False
________ junctions allow small solutes to travel between adjacent cells.
Gap
The primary structure for the processing and packaging of proteins for transport out of the cell is the _________.
Golgi apparatus
Match the stage of translation with the events that occur within it.
Initiation: mRNA binds to ribosomal subunits and a tRNA carrying methioline Elongation: amino acids are added to form a protein Termination: ribosome subunits separate and the protein is released
Match the components of the nucleus with their structure and function.
Nuclear envelope: double membrane boundary between cytoplasm and nuclear contents Nuclear pores: openings through the nuclear envelope Nucleolus: synthesizes rRNA and assembles ribosomes in the nucleus Chromosome: filamentous association of DNA and histone proteins
___________ detoxifies harmful substance produced by the cell or taken into the cell.
Peroxisomes
__________ are protein-digesting organelles in the nucleus and cytosol of cells.
Proteasomes
Select all of the following that are required for the transcription.
RNA polymerase, ribonucleotides, DNA
Which os the following is not a type of cell membrane junction?
Synapse
Peroxisomes are usually smaller in diameter than lysosomes.
True
A transmission electron microscopes (TEM) produces what kind of image?
Two-dimensional
Microfilaments are made up of trow strands of the protein ______________.
actin
A codon can code for all of the following except:
an anticodon of mRNA
The process by which cells commit suicide is called ____________.
apoptosis
Rapid digestion of a cell by its own lysosomes if called ________.
autolysis
The centrosome contains 2 _____________ that lie perpendicular to one another.
centrioles
Ion movement through small proteins in the membrane is an example of what type of diffusion?
channel-mediated
Types of transport proteins include:
channels, carriers, pumps
K+ movement out of the cell is facilitated by its ____________ ____________ gradient but opposed by the ______________ gradient.
chemical composition, electrical
A type of lipid called _____________ is scattered within the hydrophobic regions of the phospholipid bilayer, where it strengthens the membrane and stabilizes it at extreme temperatures.
cholesterol
Which of the following functions to strengthen the plasma membrane and stabilize it at extreme temperatures?
cholesterol
A 3 nucleotide unit of mRNA is known as a __________.
codon
In the cell cycle, division of the cytoplasm is called __________.
cytokinesis
The study of cells if called ________.
cytology
The _________ is the general term for all cellular contents between the plasma membrane and the nucleus.
cytoplasm
A difference in solute concentration can exist between the ___________ and the interstitial fluid because solutes are prevented from moving across the plasma membrane.
cytosol
The watery, syrup-like fluid of the cytoplasm is called ___________.
cytosol
__________ is the viscous fluid of the cytoplasm.
cytosol
The 3 components of the cytoplasm of a cell are ____________, _______________, and _____________.
cytosol, inclusions, and organelles
The 3 components of the cytoplasm of a cell are _______________, _____________, and __________.
cytosol, inclusions, organelles
Cells induced to undergo apoptosis exhibit all of the following signs:
destruction of organelles, abnormal development in plasma membrane structure, DNA degradation, condensation of the cytosol
The ______________ gradient is dependent on the combination of the ______________ gradient and the chemical concentration gradient.
electrochemical, electrical
Which of the following is NOT correct regarding simple diffusion?
energy (ATP) for the action is provided by the plasma membrane
Bulk transport refers to the movement of macromolecules across a selectively permeable membrane. There are 2 categories of bulk transport mechanisms, _____________ and ____________.
exocytosis, endocytosis
Which of the following moves across the plasma membrane easiest?
fatty acids
Exocytosis if the process whereby large molecules are secreted _________ the cell.
from
Ligands are molecules released from one cell that bind to the receptor of another cell. Which of the following are types of receptors that can bind ligands?
g protein-coupled, enzymatic, channel-linked
Body cells communicate to other immune cells that they both belong to the body and are healthy through direct contact that involves which part of the cell?
glycocalyx
The 'coating of sugar' on the cell's surface is called the _________.
glycocalyx
Proteins with attached carbohydrate groups are ____________.
glycoproteins
Peroxisomes break down harmful substances including:
hydrogen peroxide, fatty acid molecules
Which of the following are classified as plasma membrane proteins?
identity markers, receptor, enzymes, transport proteins
Desmosome membrane junctions are reinforced by what type of protein filament?
intermediate filaments
What are the 2 phases of the cell cycle?
interphase and the mitotic phase
After transcription, RNA undergoes splicing in which the ________ are removed and the _________ are spliced together.
introns, exons
Active transport mechanisms that move ions across a selectively permeable membrane are referred to as _____ pumps. Those that move one type of ion into the cell and another type out of the cells are specifically called _________ pumps.
ion, exchange
In facilitated diffusion, __________ and _____________ diffuse across a selectively permeable membrane down their concentration gradient.
ions, small polar molecules
What statements characterize smooth ER?
it can detoxify drugs, it stores lipids, it does not have ribosomes attached to it
Which statements correctly describes the nuclear envelope?
it contains phospholipids, it is continuous with the ER, it is a double membrane, it controls the entry of substances into and out of the nucleus
Which statements correctly characterize cytosol?
it contains proteins and carbohydrates, it has a high water content, it is also called intracellular fluid, it contains many dissolved solutes
Which of the following is NOT true regarding the cell membrane?
it is primarily made of cytosol
Which statements characterize prophase?
it is the first stage of mitosis, the nuclear envelope disappears, chromatin condenses into chromosomes
Which statements characterize telophase?
it is the last phase of mitosis, its processes are the reverse of prophase, it directly follows anaphase
Which statements are true regarding cholesterol?
it strengthens the plasma membrane, it is scattered within the hydrophobic regions of the phospholipid bilayer
Sister chromatids are:
joined together by a centromere, separated by spindle fibers during anaphase
Light microscopy passes _______ through the structures within a cell whereas electron microscopy uses a _____________ of ___________ to "illuminate" the specimen.
light, beam, electrons
Old or worn out organelles in a cell are removed by what organelle?
lysosomes
Which of the following are considered to be membrane-bound organelles.
lysosomes, peroxisomes, golgi apparatus, mitochondria, rough/smooth ER
Which of the following are classified as part of the endomembrane system?
lysosomes, peroxisomes, rough/smooth ER, golgi apparatus
Which of the following describe the general functions of cell.
maintain shape of the cell, dispose of wastes, obtain nutrients
The cytoplasm has 3 separate protein filament components; they are _______ filaments, _______________ filaments, and microtubules.
micro, intermediate
Internally, cilia and flagella contain cytoplasm and _______________. They are enclosed by the plasma membrane.
microtubules
One of the main factors that influences membrane permeability is __________.
molecular size
A resting membrane potential is essential in the normal function of ________ cells.
nerve, muscle
DNA wrapped around histones forms a complex knowns as a _____________.
nucleosome
The building blocks that form the double helical molecule called DNA are ____________.
nucleotides
The building blocks that form the double helical molecule called DNA are _____________.
nucleotides
The 3 components of most human body cells are a plasma membrane, cytoplasm, and _____________.
nucleus
The ________ is the cell's control center.
nucleus
The organelle in which transcription takes place is the ____________.
nucleus
During cell division, the centrosome functions to:
organize the microtubules that help move the chromosomes
The net diffusion of water across a selectively permeable membrane that is freely permeable to water but not to solute is called ____________.
osmosis
The cytosol close to the plasma contains relatively more __________ potassium than does the interstitial fluid that is close to the plasma membrane.
potassium
__________ diffusion is the most important factor in establishing the specific value of the resting membrane potential.
potassium
The 'garbage disposals' for unwanted and/or excess protein in a cell are the ___________.
proteasomes
Non-membrane bound organelles are composed of which of the following?
protein, RNA
Cells induced to undergo apoptosis exhibit all of the following signs except:
rapid replication of it's genetic material
The cis-face of the Golgi apparatus is also called the ___________ region.
receiving
Which of the following are NON membrane-bound organelles?
ribosomes, centrosomes, the cytoskeleton, proteasomes
__________ diffusion occurs when substances move across cell membranes unaided because they are either small, nonpolar, or both.
simple
Sodium diffusion into cells occurs _________ to the loss of K+.
simultaneously
Where might you find tight junctions in the body?
small intestine, urinary bladder
The synthesis of steroid hormones occurs in the _________.
smooth ER
Match the membrane-bound organelles with their structure.
smooth ER: interconnected network of membrane tubules and vesicles; no ribosomes attached rough ER: flattened intracellular network of membrane sacs called cisternae; ribosomes attached on cytoplasmic surface golgi apparatus: stacked series of flattened, smooth membrane sacs with associated transport vesicles mitochondria: double membrane structures with cristae
Which of the following is NOT an example of how cells communicate through direct contact?
the cells of hypothalamus send out pyrogens to induce fever
Which of the following statements are true regarding integral proteins?
they act as identity markers for the cell, they can act as membrane channels, they can act as receptors
Which statements are true regarding peripheral proteins?
they are attached loosely to the cell membrane, they may serve as enzymes, they cal "float" and move about the phospholipid bilayer
Which of the following statements correctly describe enzymes?
they are proteins, they are catalysts, they may be attached to the internal or the external surface of a cell
Which statements are true regarding glycolipids?
they are unique to each individual except identical twins, they are located only on the outer later of the plasma membrane
Which of the following statements are true regarding integral protein?
they can act as receptors, they can act as membrane channels, they act as identity markers for the cell
____________ junctions are found between adjacent epithelial cells and prevent substances from leaking between them
tight
The process in which mRNA copy of a gene is read by ribosomes in the cytoplasm to produce a protein is called __________.
translation
Microtubules are composed of a protein called _____________.
tubulin
Both Na+ and K+ are pumped by the Na+/K+ pumps ________ their concentration gradients in maintaining the resting membrane potential.
up
When a solute concentration exists, a _________ also exists.
water concentration
Flagellum means _______.
whip-like