Lab 1 & 2 Flashcards
When using a microscope it is important to properly set the _______ and the ______ ______ in order to visualize cell structures.
Condenser and the Iris diaphragm
Which occular lense is adjustable, has a pointer?
Left = is adjustable
Right = has a pointer
With which objective lenses do we use the coarse focus? Fine focus?
Coarse focus = 4x
Fine focus = 10x, 40x
What is the diameter of the Field of View for each objective lense?
4X (low power)?
10X (medium power)?
40X (high power)?
4X = 4.40 mm
10X = 1.75 mm
40X = 0.44 mm
All living organisms are made of ____
cells
What are the four basic features of a cell?
Plasma Membrane
Cytoplasm
DNA
Ribosomes
Which type of cell is the most complex?
Eukaryotes
What are the two groups of Prokaryotic cells?
Are they Unicellular? Or Multicellular?
Bacteria and Archaea
Unicellular
Which three things do Prokaryotic cells lack?
They lack:
1) A nucleus
2) Chromosomal proteins
3) Membrane-bound organelles
ex. mitochondria
Which type of cell is smaller? What is the advantage?
Prokaryotic cells are smaller
Advantage: allows important molecules to get to any location inside the cell quickly, without specialized organelles
What do specialized organelles do?
They facilitate transport and metabolic events
What is a bacterial cell wall composed of?
Composed of polysaccharides and amino acids
Many bacterial cells also secrete a ___________ called __________ , which _________ and ___________
Many bacterial cells also secrete a gelatinous outer covering called glycocalyx, which traps water and protects it from desiccation
Bacteria cell’s have a very thick glycocalyx called a capsule, which _______________
Bacteria cell’s have a very thick glycocalyx called a capsule, which prevents bacteria from being destroyed by an animal’s immune system
Prokaryotic cells:
Beneath the capsule is the _____ and then the _________
Cell wall and then the Plasma Membrane
Prokaryotic cell:
Define nucleoid
A central area that contains the circular molecule of DNA
Prokaryotic cells:
Smaller pieces of circular DNA is called _____
Plasmids
Which structure synthesize’s proteins?
Are they located in Prokaryotic cells?
Ribosomes
Yes
What are stains used for?
To increase contrast or emphasize selected cell features
_______ is a Cyanobacteria
Anabaena
**underline species names**
A photosynthetic bacteria is __________
Cyanobacteria
_______ is a filamentous with cells in unbranched chains, surrounded by a gelatinous sheath
Anabaena
Which 4 things do Anabaena cells contain?
(bacteria, therefore it is a Prokaryotic cell)
1) A cell wall
2) Plasma membrane
3) Cytoplasm
4) Heterocyst
In Anabaena, where does photosynthesis occur? (since the cytoplasm does NOT contain any membrane-bound organelles)
Photosynthesis occurs in the layers of photosynthetic membranes called thylakoids
T or F: Most organisms are able to use atmospheric Nitrogen (N2) directly
False;
Most organisms are UNABLE to use atmospheric Nitrogen (N2) directly.
They depend on other organisms to convert the nitrogen into a form that they can use
Nitrogen is essential for the ___________ and _________ (____ and _____) within an organism and is often a _________ for the growth of algae.
Nitrogen is essential for the synthesis of proteins and nucleic acids (RNA and DNA) within an organism and is often a limiting nutrient for the growth of algae.
How does Anabaena receive its nitrogen?
What kind of cell does this make it?
It fixes its own Nitrogen within its heterocyst,
therefore it is a multicellular cell because it has the presence of the specialized heterocyst within the filament
Where is the DNA material stored in a Prokaryotic cell?
In the nucleoid
Since there are no mitochondria or chloroplasts in theses cells:
1) Where does the cellular respiration occur in bacteria?
2) Where does cellular respiration and photosynthesis occur in Cyanobacteria?
1) Cytoplasm
2) Thylakoids
What kind of Eukaryotic cells are there?
Plant cells and Animal cells
Eukaryotic cells typically have _______ and ____________
Eukaryotic cells typically have a membrane-bound nucleus and a variety of other membrane-bound organelles.
Elodea (or other aquatic plant):
What are the 6 components of this plant?
1) Cell wall
2) Plasma membrane (pressed tightly against cell wall)
3) Cytoplasm
4) Chloroplasts (where photosynthesis occurs)
5) Large central vacuole - large and colorless
(pushes the cytoplasm and chloroplasts against the membrane)
6) Nucleus (colorless)
The movement of many tiny particles in the cytoplasmic strands of a cell is called ____________
Cytoplasmic Streaming
How does the size of Eukaryotic Elodea cell compare to a Prokaryotic Anabaena cell?
The Elodea cell is bigger then the Anabaena cell in size
For which experiment did we use methylene blue stain?
With our cheek epithelial cells
“Animal cells”
Animal Cells:
What are the 3 components of a cheek cell?
1) Irregular shaped Plasma membrane with numerous folds…
2) … which encloses the granular cytoplasm
3) A small, dark stained nucleus
Animal vs plant cells
Cheek vs Elodea*
Which one is bigger?
In this case the animal cell is bigger then the plant cell
What is the purpose of methylene blue stain ?
- The stain is used to increase contrast
- It stains the DNA molecules of the nucleus dark blue
- Allows us to see the cell and its components more clearly
What are Eukaryotic cell walls made of?
Plant cell = cell wall is made of cellulose
Animal cell = no cell wall
Which type of cell has plastids?
Name the 3 plastids
Only plant cells!
Chloroplasts
Chromoplasts
Leucoplasts
what are the hairs of Tradescantia composed of?
What color are they? Why?
They are composed of a chain of long cells
They are colorless but turn purple as they mature, due to anthocyanin (stored in central vacuole)
What type of cell is Tradescantia?
It’s a plant cell
Which 7 components make up a Tradescantia cell?
1) Cell wall
2) Plasma membrane (tightly against cell wall)
3) Nucleus
4) Nuclear envelope
5) Central vacuole
6) Cytoplasm
7) Mitochondria
What is the function of a cell wall?
Protects and gives rigidity to the cell
What is the function of the plasma membrane?
- It regulates the passage of substances into and out of the cell
* It is selectively permeable (only allows some stuff in)
What are the two main functions of a nucleus?
1) It controls cell function (by directing protein synthesis)
2) It stores the genetic material (DNA)
What surrounds a nucleus?
A double membrane called the nuclear envelope
A large colorless organelle called _______ occupies 85-90% of the total cell volume. It gives support to the plant cell when it is fully expanded and functions in ______ of water as well as ____,____,_____ and _____
Central vacuole
storage of water as well as enzymes, ions, proteins and toxins
What does the Tradescantia also store in the central vacuole?
It stores purple pigment called Anthocyanin
How do we observe the cytoplasm in Tradescantia? Why? What is in the cytoplasm?
We observe the cytoplasm as cytoplasmic streaming.
Because the large central vacuole takes up most of the cell, therefore it is restricted to a small layer
Mitochondria
Mitochondria are the site of __________, a process that generates rich molecules called ___________ from ______
Cellular respiration
Adenosine Triphosphate (ATP)
sugars
*ATP is the primary source of energy for cellular processes
Onion (Allium) cells:
1) Is there cytoplasmic streaming?
2) Why do the cells lack pigment?
3) How can you identify the cell as a plant cell?
1) Yes
2) They are found underground and are not photosynthetic
3) The cell wall and large central vacuole
What are Chloroplasts?
Chloroplasts are plastids that contain pigments called chlorophylls and they are site of the photosynthesis
Define Photosynthesis
The use of energy to synthesize sugars from carbon dioxide and water
The color of chloroplasts is due to ____ a ________. This is located on the _______ of the chloroplast This pigment ____________
Chlorophyll
Green pigment
Thylakoid membranes
Captures light energy used in photosynthesis
What are the components that make up a green pepper cell?
1) Cell wall
2) Chloroplasts
3) Cytoplasm
4) Central Vacuole
5) Nucleus
Chromoplasts are plastids that contain pigments called ___, and are typically _______ in color. They are commonly found in _____ and ______.
Carotenoids
Yellow, orange, red, dark purple
Flowers (color attracts animals for pollination) and fruits (seed dispersal)
What components make up a red pepper?
1) Cell wall
2) Chromoplasts
3) Cytoplasm
4) Central vacuole
5) Nucleus
Leucoplast refers to a group of __________ that function in the _____ of _______, _______, ______
Non-pigmented plastids
storage of starch, proteins, fats (lipids)
Where do we find Leucoplasts in a cell?
Around the nucleus
In the banana (Musa), the leucoplasts form ______.
Where are they located and how?
Large starch grains.
Located free in the cytoplasm because the starch grains are so big that they have outgrown the leucoplast
What are the componants of a Musa?
1) Cell wall
2) Starch grains
3) Cytoplasm (streaming)
4) Striations (if visible) - on starch grains
What do we add to the Musa to be able to see the starch grains?
We add a drop of iodine-potassium iodide (IKI) to stain the starch grains dark brown/purple
Which specimen appears as a tiny white star shape?
What type of cell is it
Amoeba
Unicellular animal cell
What are the six parts to an Amoeba?
1) Plasma membrane
2) Pseudopodium
3) Cytoplasm
4) Nucleus
5) Contractile vacuole
6) Food vacuole
What is the pseudopodia?
It is cellular extensions that form as the granular cytoplasm flows forward (allows organism to crawl)
The cytoskeletal components responsible for pseudopod formation are ______ which are composed of ?
Microfilaments
*help it move*
Composed of actin subunits, involved in cytoplasmic streaming and division of cytoplasm
What is phagocytosis?
In the Amoeba
It uses the pseudopodia to encircle and trap small animals and food particles.
What does the contractile vacuole look like?
What is its function?
Why may it vanish?
Colorless and perfectly circular.
Functions in osmoregulation (maintenance of a constant internal solute)
Vanishes as it contracts to empty its contents (excess water)
Which type of cytoskeletal components are cilia and flagella made up of?
Microtubules
*for mobility*
What works against microtubles to create a bend in the cilium of flagellum?
Specialized (motor) proteins
Causes oar-like movement of cilia
Causes whip-like movement of flagella
How did we slow down the Paramecium?
Using a drop of PROTOSLO to down down the organism, then we can see the cilia
Why does the cell need mitochondria in abundance?
To supply the cilia with ATP
What is the function of a nucleolus?
Where ribosome subunit assembly occurs
What is the funtion of the Golgi?
To modify, ship and store products of the ER
What is the function of the secretory vesicles?
The secretion of proteins
What is the function of the Rough ER?
The sorting of proteins
What type of cell transports proteins?
Animal cell
What passes out of nuclear pores?
mRNA and tRNA
Ribosome subunits
What is the function of the cristae of mitochondria?
They increase the surface area available for ATP synthesis
What is the function of smooth ER?
Lipid synthesis and modification
No ribosomes
What are lysosomes?
Small membrane bound organelles that contain hydrolytic enzymes that digests a cell’s food and waste
What is the function of the Rough ER?
Studded with Ribosomes
Key role in the initial synthesis and sorting of proteins for export
What are vesicles?
Small membrane bound organelles, found in Eukaryotic cells
May contain macromolecules (proteins, lipids) for storage, transport or secretion
