Chapter 3 Quiz Questions Flashcards
Name the 3 principal parts of a generalized cell
PCN
- Plasma Membrane
- Cytoplasm
- Nucleus
What are the principal constituents of the plasma membrane?
ICC-CLP
- Integral Protein
- Channel
- Carbohydrate
- Cholesterol
- Lipid Bilayer
- Peripheral Protein
What is an integral membrane protein?
A protein that is embedded into the cell membrane permanently. It penetrates through the membrane.
What is a peripheral protein?
A protein that is attached to the surface of the cell membrane at different times.
What are the 2 types of membrane proteins?
- Integral
- Peripheral
What are 3 functions of cell membrane?
- They keep toxic substances out of the cell.
- They have protein receptors and channels that allow specific molecules to mediate cellular and extracellular activities between organelles and between the out and inside env.
- Separate vital but incompatible metabolic processes conducted within organelles.
What is the name of the fluid inside a cell?
Outside a cell?
- Intracellular fluid
- Extracellular Fluid
Define Active Transport
The movement of substances across the membrane using ATP. Usually moves things from low to higher concentration gradient.
Define Passive Transport
The movement of substances across the membrane without expenditure of cellular energy. Usually from high to low concentration.
Define Osmosis
The diffusion of water across a selectively permeable membrane from a region of high water concentration to a low water concentration.
Define the difference between hypotonic and hypertonic
Hypotonic: A solution that has a lower concentration of solutes than another solution.
Hypertonic: A solution that has a higher concentration of solutes than another solution.
What is cytosol in a cell?
The jelly-like substance within the cell that provides the fluid medium necessary for carrying out biochemical reactions.
Describe the structure of a nucleus (4)
Consists of a nuclear envelope, which consists of a double lipid bilayer. Also contains nuclear pores which allow materials to go in and out of the cells. Also has nucleolus and chromatin.
Describe the structure and location of the ribosomes.
Serve as protein site of protein syntheses, made of 2rRNA units that wrap around an mRNA to start translation. Found in cytoplasm and are attached to rough ER.
Describe the function of lysosomes.
They are organelles with enzymes that break down and digest unneeded cellular components.
What is the function of microtubules?
- Maintain cell shape and structure
- Help resist compression of cell.
- Play role in positioning of organelles in the cell.
Identify the primary function of cilia.
Help move dust, mucus, and bacteria upward through the airway; away from lungs.
What is the cytoskeleton?
A group of fibrous proteins that provide structural support foe cells, help with cell motility, reproduction, and transport
What are the cytoskeleton proteins with smallest diameter called?
Microfilaments
Describe Transcription
The process of producing an mRNA molecule that is complementary to a particular gene of DNA.
Describe Translation
The process of synthesizing a chain of amino acids.
Fill in the appropriate RNA nucleotide that would be expected to pair with the DNA nucleotide shown below:
C–T–T–A–G–A–G–A–T—G
G-A-A-U-C-U-C-U-A-C
The process of transcription provides which 3 types of RNA?
mRNA, rRNA, tRNA
What is an anticodon?
The sequence of 3 bases on the tRNA molecule. Allows tRNA to bind to a specific sequence of 3 nucleotides on mRNA.
What is a termination (stop) codon?
A codon that signals the termination of the translation process of the current protein. 3 nucleotides.
What is a gene? What is its function?
A functional segment of DNA that provides genetic info necessary to build a protein.
It provides the code necessary to construct a particular protein.
For successful cell division to occur, the cell must undergo mitosis followed by cytokinesis. Explain these 2 terms.
Mitosis: The division of genetic material, during which the cell nucleus breaks down and 2 new nuclei are formed.
Cytokinesis: The dividing of 2 cytoplasms into the two distinctive cells.
What do the carbohydrate molecules attached to glycoproteins do?
They help aid in cell recognition. They also extend from membrane proteins and some membrane lipids collectively to form the glycocalyx.
What are the 4 phases of mitosis which take place after interphase?
- Prophase
- Metaphase
- Anaphase
- Telephase
What are the 4 phases of interphase?
- G1
- S
- G2
- G0
What happens during G1?
Cells grow
A cell can spend a couple hours to multiple days in this phase.
What happens during S phase?
Cells replicate their DNA, typically lasts 8-10 hrs
What happens during G2 phase?
Cell continues to grow and make necessary changes to prepare for mitosis.
Lasts about 5hrs
What happens at G0 Phase?
Cells temporarily stop dividing and are resting.
At this point, cells have permanently ceased dividing.
What is a sister chromatid?
One of a pair of identical chromosomes.
How is Prophase broken down?
Prophase –> Early metaphase + Prometaphase
What happens during early metaphase? (3)
Cell breaks down some structures and builds up others.
Loosely packed chromatin coils up and condenses into visible chromosomes.
Miotic spindle begins to form.
What happens during pro-metaphase? (4)
Miotic spindle begins to capture and organize the chromosomes.
Chromosomes become even more condensed.
Nuclear envelope fully broken down, releases the chromosomes.
Miotic spindle grows more, and some microtubules capture chromosomes
What happens during metaphase? (2)
Miotic spindle has lined up all chromosomes at the centre of the cell along a linear plane.
The microtubules pull apart the sister chromatids and bring one from each pair to each opposite end of the cell.
What happens before proceeding to Anaphase?
The cell will make sure all the chromosomes are at the metaphase plate with their kinetochores correctly attached to microtubules.
What happens if the kinetochores are not correctly attached to microtubules?
Then the cell will halt division until the problem is fixed.
What happens during Anaphase? (3)
- Sister chromatids are separated from one another, forming individual chromosomes once again.
- Chromosomes are pulled to opposite ends of the cell.
- Each end of the cell receives one partner from each pair of sister chromatids.
What are the first 3 things that happens during Telophase?
- The cell starts to re-establish its normal structures as cytokinesis takes place.
- Two new daughter nuclei are at either end of the dividing cell, one for each set of chromosomes.
- The nuclei surround the genetic material.
What are the other 3 things that happen during telophase?
- Nucleoli reappear within the new nuclei.
- Spindle fibres break apart.
- Each cell gets its own DNA, organelles membranes, and centrioles
What are the 5 classifications of stem cells?
TPMOU
- Totipotent
- Pluripotent
- Multipotent
- Oligopotent
- Unipotent
What is a Totipotent stem cell?
Embryonic cells that have the ability to differentiate into any type of cell and organ in the body.
What are pluripotent cells?
A stem cell that has the potential to differentiate into any type of human tissue, but can’t support the full development of an organism.
What are multipotent cells?
Stem cells that have the potential to differentiate into different types of cells within a given cell lineage or small number of lineages.
What are oligopotent stem cells?
A stem cell that is limited to becoming one of a few different cell types.
What are unipotent stem cells?
A fully specialized stem cell that can only reproduce to generate more of its own specific type of cell.
What are the 3 distinct types of stem cells in adult bone marrow?
HWP
- Hematopoietic stem cells
- White blood cells
- Platelets.
The cellular contents located between the outer limiting membrane of a cell and its nucleus are collectively known as what?
Cytoplasm
Which lipids compose approximately three-fourths of the lipids in the plasma membrane of a human cell?
Phospholipids
Which cell organelle is the site of fatty acid, phospholipid, and steroid synthesis?
Smooth ER
What is not true about vesicular transport?
In bulk-phase endocytosis, the cell membrane folds inward and forms a pinocytic vesicle, which allows a droplet of extracellular fluid to flow inwards and surround the liquid.
Human cells are basically factories that produce large numbers of diverse what?
Proteins
The only example of a flagellum in the human body is in the:
Tail of a sperm cell
What is NOT a characteristic of the plasma membrane?
Provides the foundation for cell organelles.