Exam 1 Flashcards
In your own multicellular body, cell with different functions have different DNA.
False
Compared to bacteria which of the cell types below are not responsible for finding food?
Lymphocyte, Macrophage, Fibroblast.
A cancer cell will be anchorage-dependent for growth an immortal
False
A cell that is anchorage-dependent for growth will also exhibit contact inhibition.
True
In your own multicellular body, different cells in your body have a division of labor between them.
True
The Paramecium swims by way of using a flagella.
False
The contractile vacuole of the paramecium is possibly an evolutionary precursor of the kidney.
True
What is the major difference between a single-celled Eukaryotic organism and a multicellular organism?
Division of labor
A cell that is itself and organism must have a minimum of four factors to survive:
1) Finding food
2) Finding shelter
3) Finding a mate
4) Reproduction
A normal cell is anchorage-dependent for growth and mortal.
True
A single-celled Eukaryotic organism:
1) Has a limited # of biomolecular machines
2) Has the four needs
3) Escape predators
Ribosomes bound to some of the membrane invaginations in the endomembrane theory.
True
Loss of the cell wall is required for the endosymbiotic theory.
True
In an extant prokaryotic cell, the outer boundary of life is the capsule.
False
The end of the retraction fiber touching the cell culture plate still contains the cell equivalent of super glue.
True
What limits how big a cell can be?
The surface area to volume ratio.
The presumed first step in the transition of the primitive, proto-prokaryotic cell into the primitive, proto-eukaryotic cell was the loss of the cell wall.
True
A normal cell is ____ and _____ for growth.
Anchorage-dependent, mortal
It is presumed that the peroxisomes evolved in these primitive, proto-eukaryotes to remove oxygen, which was toxic to the primitive cells.
True
Motility improved the fitness of these early cells because:
it allowed them to move away from predators and towards food.
Fluorescent Microscopy is a form of light microscopy.
True
TEM provides a thin, two-dimensional section of the object being studied.
True
After a cell is pancake shaped in a cell culture dish, the order of events that occurs as a cell walks is:
Filopodia, Lamellipodia, cell muscle, retraction fiber.
FLCR
List one limitation of the cell culture technique.
Not all cells grow in culture.
The cytoskeleton gave rise to the nuclear envelope.
False
When cancer cells are crowded by surrounding cells, the cancer cells become spherical & they can still go through cell division.
True
DNA in extant prokaryotic cells is circular.
True
The ancient earth did not contain much oxgyen.
True
The cytoskeleton enabled the primitive cell to become motile.
True
Write a few sentences that explain what limits an individual cell from becoming more complex.
An individual cell, meaning that it is a single-celled, is limited from becoming more complex because it has a limited number of biomolecular machines and does not have a division of labor among cells as a result of being single-celled. An individual cell has to do all of the work, with no division of labor, and has limited space within the cell which limits it from becoming more complex.
What limits the paramecium from developing more complex functions?
The paramecium is a single-celled organism, meaning that its cells must change/rearrange based on need. The lack of division of labor within the paramecium limits its ability to develop more complex functions. The paramecium is limited by the number of biomolecular machines it can contain within itself as a result of lack of space.
The association of ribosomes with ____ invaginations would support the ____ theory.
membrane, endomembrane
For a protein to enter the endoplasmic reticulum as part of the endoplasmic reticulum’s lumen or part of the endoplasmic reticulum’s membrane:
A ribosome binds to the mRNA and a short stretch of protein is synthesized that contains a signal sequence.
Amino acids can be largely subdivided into two groups. What are the two groups?
1) Hydrophobic
2) Hydrophilic
It is a simple matter (i.e. thermodynamically favorable) for a vesicle to form the endoplasmic reticulum.
False
The ER is contiguous with the Golgi apparatus.
False
What are the two functions of a membrane?
1) To protect the cell, acting as a barrier
2) To control cell movement
We are made up of ___ percent water.
50-70
What is the difference between a single-pass transmembrane protein and a 7-pass transmembrane protein?
A single-pass transmembrane protein can only pass through the phospholipid bilayer once, and cannot create an ion channel. A 7-pass transmembrane protein passes through the phospholipid bilayer 7 times, which creates a channel for ions.
What is the difference between a triglyceride and a phospholipid?
A triglyceride has 3 fatty acids, and a phospholipid has only two fatty acids.
Explain how vesicles are carried from the Golgi apparatus to the plasma membrane.
Vesicles are passed to filaments from the Golgi apparatus which assist vesicles in fusing into the plasma membrane.
Active transport uses ATP to move components in parallel with their concentration gradient, that is: from a high concentration to a low concentration.
False
The ER is contiguous with the nuclear envelope.
True
Explain the evolutionary origin of the endoplasmic reticulum, Golgi apparatus and vesicles.
Endomembrane theory: loss of the cell wall and infolding occurs.
If something is soluble in water and a shell of hydration forms around it, it is termed:
Hydrophilic
Cholesterol is ___ to have in biological membranes.
Good
The plasma membrane gets new lipids from:
- The lumen of the ER
- The lumen of the Golgi apparatus
- Making new lipids at the plasma membrane
- The nucleus
- None of the above
None of the above.
What are the orphaned organelles orphaned from?
Orphaned organelles: mitochondria and chloroplast.
They are orphaned from the endomembrane system.
When a vesicle fuses with the plasma membrane the contents of the lumen of the vesicles are:
Ligands that are used in cell communication.
Facilitated diffusion uses a channel protein to let components move down their concentration gradient.
True
A single-pass trans-membrane protein that is an alpha helix can make a channel.
False
Molecular motors use ATP as the energy source to power the molecular motors.
True
Consider the geography of cells. Actin filaments are present in the cell’s ___ and the microtubules are present in the cell’s ___.
Cortex, Interior
Where is the histone H1 found?
On the outside of the nucleosomal core. Histone H1 acts like a “staple” that holds together the wrapping of DNA around the nucleosomal core.
The diameter of an intermediate filament is 25 nm.
False
Heterochromatin does not exist in interphase nuclei.
False
Chromosomes are made out of Euchromatin.
False
Which cytoskeletal filament system lines the inside of the nucleus to protect it?
The Intermediate Filament System
Molecular motors run on which two cytoskeletal filament systems?
The Actin Filament System
The Microtubule System
To get into the nucleus a component has to have to correct signal sequence and pass through a nuclear pore.
True
The actin filament system is present in the nucleus.
False
Cilia and microvilli contain a similar number of parallel actin filaments.
False
Naked DNA does not exist in Nature but scientists can make naked DNA in a test tube.
True
What does the nucleosomal core have in it (i.e., the basket ball like structure on the slides)?
8 histones–two H2A, two H2B, two H3 and two H4.
The actin filament system extends outside of the cell.
False
There is communication between cells and communication ___ cells.
Within
There are two basic forms of cytoplasmic signaling (i.e., signal transduction). One uses ___ and the other uses ____.
Calcium, Protein
When insulin binds to a receptor, this signal first uses _____.
kinases
MAPK has two different functions depending on where this kinase acts in the ___ ____. If the kinase becomes active during interphase the cell is triggered to progress through the ___ ____.
Cell cycle, Cell cycle.
For a cell to respond to a ligand released from a cell and uses the circulatory system to get to the responding cell it is called ____ communication.
Endocrine.
The other point where MAPK can become active is ___ of the cell cycle.
m phase
Two types of second messengers discussed in lecture can exist downstream of a plasma membrane receptor. These are ___ and ___.
cAMP (cyclic AMP) and MAPK (MAP kinase).
There are two basic types of communication within cells. One type is called ___ signaling and it takes days to weeks to occur. The other type is called ____ communication and it takes minutes to hours to act.
Nuclear, Cytoplasmic
When a cell “talks to itself” it is called ____ communication.
Autocrine
For a cell to respond to a ligand released from a neighboring cell where the ligand diffuses directly from one cell to another is called ___ communication.
Paracrine
There are two types of receptors. One type of receptor binds to polar (hydrophilic) ligands and this is the receptor located in the ___ _____.
Plasma membrane
At these checkpoints, a cyclin works with a cyclin-dependent kinase (i.e. CDK) to regulate the checkpoint.
True
The synthesis/presence of cyclin is what turns on the CDK as the CDK is always present but it is the cyclin that is synthesized and degraded in cycles.
True
In the time span of 10 years every cell in your adult body goes through the cell cycle.
False
List the three categories of cells in the body with regard to the cell cycle.
1) those cells that never go through the cell cycle after birth (ex: muscles and neurons)
2) those cells that go through the cell cycle by injury (ex: kindney)
3) those cells that constantly go through the cell cycle (ex: skin, blood cell production).
After DNA synthesis (i.e. S-phase), an identical copy of the DNA has been made and this is present in the two chromatids when viewed as the chromosome.
True
Many chemotherapy drugs act by arresting the cell in M-phase of the cell cycle.
True
The ___ begins to be destroyed at the metaphase of the cell cycle causing the chromosomes to begin to ____.
Cyclin B1, decondense
Cytoplasmic signal transduction controls the checkpoints of the cell cycle.
True
An important checkpoint regulator is at the Gap2/M-phase transition. Here cyclin B and CDK1 activate and form MPF which becomes a ____ ____ and causes the DNA to condense into ____.
histone kinase; chromosomes
In your body not all cells go through the cell cycle.
True
Gap 1 of the cell cycle represents the time when the cell is doing what it is supposed to do as part of its cell type. In other words, that is when a liver cell is going its function as a liver cell.
True
Cancer can be described as a loss of cell cycle regulation.
True
During mitosis, the cytoplasm of the cell is “settled down.”
True
The activation of both MPF and MAPK result in ____ ___ of the cytoplasm during M-phase.
settling down
Cytokinesis in a plant and animal cell takes two forms. List them here.
In a plant cell: phragmoplast formation
In an animal cell: contractile ring formation
