Unit 4-Cellular Structure Flashcards
Define a light microscope
Visible light is passed through a specimen such as a microorganism or a thin slice of tissue and shown through the glass lens. The lenses bend the light that magnifies the specimen
Define micrograph
Tells you that the photograph was taken through a light microscope and that this image is 230 times the actual size of the organism
How big are most cells in diameter
Between 1 and 100 micrometers
Define resolution
A measure of the clarity of an image
Define an electron microscope
Forces a beam of electrons through a specimen
Can distinguish super small things
Large cells have more surface area then small cells but much less of what
Surface area relative to their volume then small cells
Define the plasma membrane
Forms a flexible boundary between the living cell and its surroundings
Explain the structure of a plasma membrane
A head with a negatively charged phosphate group and two non polar fatty acid tails
Considered a phospholipid bilayer
What part of the phospholipid bilayer is hydrophobic and hydrophilic
The tails face each other into the centre of the bilayer because they are hydrophobic
The heads face the exterior because they are hydrophilic
What basic features do cells have in common
Bounded by a plasma membrane Have one or more chromosomes Contain ribosomes Cytoplasm Flagella (built differently)
What do only eukaryotes have
Nucleus Endoplasmic reticulum Golgi apparatus Lysomes Vacuoles Mitochondria Chloroplasts (only in some eukaryotes)
What are only in prokaryotes
Nucleoid (like the nucleus) Cell wall (some eukaryotes have)
What does the nucleus and ribosomes do
Carry out the genetic control of the cell
What organelles are involved in the manufacture distribution and breakdown of molecules
Endoplasmic reticulum Golgi apparatus Lysosomes Vacuoles Peroxisomes
What does the mitochondria do
Process energy
What organelles are responsible for structural support movement and communication
Cytoskeleton
Plasma membrane
Plant cell wall
What organelles are not found in plant cells
Lysosomes and centrioles
What structures are only found in plant cells
Has a ridge cell wall
Chloroplasts
Central vacuole
When a cell is not dividing the complex proteins and DNA is called what
Chromatin
What happens to the chromatin when a cell begins to divide
It begins to coil up more and become chromosomes
What is around the nucleus
A membrane called the nuclear envelope
What is the nucleolus
A structure in the nucleus that is the site where ribosomal RNA is synthesized according to the instructions in the DNA
What are the ribosomes
Makes the proteins
Use the instructions from the nucleus to carry out protein synthesis
Define the endomembrane system
Internal membranes and organelles are found within
Functions of the smooth ER
Important in the synthesis of lipids
Such as sex hormones
Functions of the rough ER
Make more membrane
Produce proteins and transported by the ER
Process of protein transport
Proteins made by ribosomes and are sent into the ER.
Packaged into a transport vesicle and moved and then buds off from the ER
Where do most transport vesicles travel to after leaving the ER
The Golgi apparatus
What are functions of the Golgi apparatus
Wear house and finishing factory
One side serves as a receiving dock then are modified through the Golgi and the other side is the shipping side that sends the vesicle off again
What is the function of lysosomes
Contains digestive enzymes
It breaks down damaged organelles and recycles their molecules
What are the functions of vacuoles
Large vesicles that have a variety of function such as general maintenance of the cell
Function of the mitochondria
Carry out cellular respiration by converting the chemical energy to ATP
What increases the surface area in the mitochondria
The cristae
Where does the mitochondrial DNA and ribosomes found and many enzymes for cellular respiration
The mitochondrial matrix
What is the function of chloroplasts
Photosynthesizing organelles of all photosynthetic eukaryotes
Where is chloroplast DNA and ribosomes and enzymes found
In a thick fluid called the stroma
What are thylakoids
A network of interconnected sacs inside the chloroplasts
Each stack of thylakoids are called a granum
Define a cytoskeleton
A network of protein fibres that extend throughout
Used for cellular structure and motility
What are microfilaments
Also called actin filaments
Important in animal cells for structure and movement
What are intermediate filaments
Made of various fibrous proteins that reinforce cell shape and anchor organelles
What are microtubules
Hollow tubes important for structure as well
What are cilia
Short appendages that are used to help protists move
What is a flagellum
Longer then cilia and used for movement
What is the extracellular matrix
A layer that helps hold cells together in tissues and protects and supports the plasma membrane
What are integrins
Membrane proteins
What are the three types of cell junctions found in animal tissues
Tight junctions
Anchoring junctions
Gap junctions
The ultra structure of a chloroplast is best studied using what
Transmission electron microscope
The cells of an ant and a horse are on average the same small size what is the main advantage of small cell size
Small cells can better take up sufficient nutrients and oxygen to service their cell volume
What would tell you whether s cell is prokaryotes or eukaryotes
Whether or not the cell is partitioned by internal membranes
What correctly describes bound ribosomes
Bound ribosomes generally synthesize membrane proteins and secretory proteins
In which cell would you find the most lysosomes
White blood cell that engulfs bacteria
In which cell would you find the most mitochondria
Muscle cell in thigh of long distance runner
In which cell would you find the most smooth ER
Ovarian cell that produces the steroid hormone estrogen
In which cell would you find the most rough ER
Pancreatic cell that secretes digestive enzymes
In which cell would you find the most tight junctions
Cell tissue layer lining digestive tract
What is the path a protein takes from the site where it’s polypeptides are made to its export
Rough ER
Golgi apparatus
Transport vesicle
Plasma membrane
