Module 3: Cells Flashcards
Where is a cell’s genetic information is contained?
Nucleus
Cells depend on which organelle for energy?
Mitochondria
What is the cytoskeleton?
The framework of the cell
Define Isotonic
A solution with the same concentration of solutes as that inside the cell.
Define Hypotonic
A solution with a higher concentration of solutes as that inside the cell.
Define Hypertonic
A solution with a lower concentration of solutes as that inside the cell.
What is Osmotic pressure?
the water pressure that develops from osmosis.
What is Endocytosis?
Brings substances into the cell
What is Exocytosis?
Uses vesicles to release substances outside the cell
What is Osmosis?
Diffusion of water across a selectively permeable membrane
What is diffusion?
Movement of particles or molecules from an area of high concentration to an area of low concentration
What is the Sodium-Potassium pump?
It moves sodium ions out of cells & potassium ions into cells
Why do you think nerve cells have long extensions?
To quickly transmit electrical impulses from one part of the body to another
Why do you think muscle cells can shorten?
To allow body parts to move
Why are RBC’s concave?
The shape allows these cells to bend and squeeze through tiny blood vessels
What is the plasma membrane?
Surrounds the cell. Regulates the passage of substances into and out of the cell.
What is the nucleus?
The control centre of the cell. Contains the genetic information
What is the cytoplasm?
Substance that fills the space between the plasma membrane and the nucleus.
What does the plasma membrane consist of?
Phospholipids, cholesterol and proteins
What is the role of cholesterol molecules in the plasma membrane?
to stiffen and strengthen the plasma membrane
What does selectively permeable mean?
That some substances such as lipid-soluble molecules pass through easily while others do not
What type of cells contain more than one nucleus?
Liver cells and skeletal cells
What type of cells do not have a nucleus?
Mature red blood cells
What is the nuclear envelope?
A double-layered membrane surrounding the nucleous
What is the role of nuclear pores?
Regulate the passage of molecules into the nucleus
What are Chromatin?
Thread-like structures composed of DNA and protein
What is the role of the nucleolus?
Manufacture components of ribosomes, the cell’s protein-producing structures.
What is the Endoplasmic Reticulum?
network of membranous canals and curving sacs
What is the role of Ribosomes?
Synthesize protein
What is the role of smooth Endoplasmic Reticulum?
Contains enzymes that synthesize certain lipids and carbohydrates
What is the role of the Golgi Apparatus?
prepares and packages proteins for export to other parts of the body
What is the cristae of the mitochondria?
Folding membranes
What is the role of the enzymes found between the spaces of the cristae?
The organelle uses to convert organic compounds into ATP which cells use for energy
Why do some cells contain more mitochondria than others?
Cells that do more work need more energy
What is the role of the cytoskeleton?
The supporting framework of the cell- determines the shape of the cell, gives it strength, and also allows the cell to move.
What is passive transport and what does it include?
Don’t require the cells to expend energy. It includes diffusion, osmosis, filtration, and facilitated diffusion.
What is active transport?
Solutes move up the concentration gradient from areas of lesser to greater concentration.
What would happen to an RBC in an isotonic solution?
Water moves in and out of the cell at an equal rate?
What would happen to an RBC in a hypertonic solution?
Water will diffuse out of the cell causing it to shrivel and perhaps die
What would happen to an RBC in a hypotonic solution?
Water will move by osmosis into the cell causing the cell to swell and eventually burst
What is filtration?
Difference in pressure- water and dissolved particles are forced across a membrane from an area of higher to lower hydrostatic pressure
What is facilitated diffusion?
Molecules helping other molecules to move across the membrane
What is endocytosis?
A form of vesicular transport that brings substances into the cell
What is phagocytosis?
Cell eating. Occurs when engulfs a solid particle and brings it into the cell.
What is pinocytosis?
Cell drinking. Occurs when tiny vacuoles bring droplets of extracellular fluid containing dissolved substances into the cell.
What is exocytosis?
Uses vesicles to release substances outside of the cel
What is the role of DNA?
Stores all of a cell’s genetic information needed to develop, function and maintain itself.
DNA is a polymer, what does that mean?
It is a large molecule made up of many smaller molecules joined together in a sequence that encodes the cell’s genetic information.
What are the building blocks of DNA?
Adenine, Thymine, Guanine, and Cytosine
Why does DNA need help from RNA?
Because DNA is too large to leave the nucleus and protein synthesis takes place in the cytoplasm
What is transcription?
When the nucleus receives a chemical message to make a new protein, the segment of DNA with the relevant gene unwinds.
What is translation?
The ribosome moves along the strand of mRNA reading the codons
What happens in prophase?
Chromatin beings to coil and condense to form chromosomes, each duplicated chromosome consists of two strands and each contain a single molecule of DNA. The two join together in the middle at a spot called the centromere, centrioles move to opposite poles of the cell, the nuclear envelope dissolves and spindle fibers form in the cytoplasm
What happens in metaphase?
Some of the spindle fibers attach to one side of the chromosomes at the centromere, the chromosomes line up along the center of the cell.
What happens in Anaphase?
The centromeres divide forming two chromosomes instead of a pair of attached chromatids, the spindle fibers pull the newly formed chromosomes to opposite poles of the cell
What happens in Telephase?
A new nuclear envelope develops around each set of daughter chromosomes, the spindle fibers disappear and the cytoplasm divides to produce two identical daughter cells.
What are organelles?
The structures within the cell that perform specific tasks in cellular metabolism
