Microbiology, Cell Biology and Tissues Flashcards
What are the 3 main parts of an eukaryotic cell?
Nucleus, Cytoplasm, and Cell Memebrane.
What is the name for everything inside the cell membrane?
Protoplasm.
What are the 2 parts of both prokaryotic and eukaryotic cells?
The Cell Membrane and the Protoplasm.
Do prokaryotic cells contain nuclei?
No. Prokayrotic cells have a nucleoid region where genetic material is stored.
What is a nucleoid?
A region in prokaryotic cells where genetic material is stored. Separate from plasmid.
What is a plasmid?
Extrachromosomal DNA. They are circular strands that replicate independently from chromosomal DNA in bacteria and protozoa. They can be transferred (even between species) through conjugation. This is how bacteria become resistant to antibiotics so quickly.
What is the difference between a prokaryotic cell and a eukaryotic cell?
Prokaryotes are always small, unicellular, and lack a true nucleus.
Eukaryote means “true kernal” in Greek. How does that define its biology?
Eukaryotes have a membrane bound nucleus. They also have other membrane bound organelles, are larger and often multicellular.
What makes up the cytoplasm of a eucaryotic cell?
Cytosol, cytoskeleton, and organelles.
What is cytosol?
The aqueous medium of the cytoplasm containing molecules and macromolecules.
What is the nucleoplasm?
The matrix of the nucleus.
Are the nucleus and nucleolus organelles?
The nucleus is. It is membrane bound, and therefore, an organelle. The nucleolus is not membrane bound, and so it cannot be called an organelle. The nucleolus is the dense, sperical area within the nucleus that produces and assemble ribosomes.
Is the nucleus always present in eucaryotic cells?
No. It’s a trick question. At the start of mitosis, the nucleolus disappears, the chromosomes condense, the nuclear membrane breaks down, and the contents of the nucleus spill into the cytoplasm. Then, it all reassembles in the two daughter cells. Also, mature RBCs do not have nuclei.
What is the primary purpose of the cell membrane?
To control what goes in and out of the cell.
What is the biggest cell in the human body?
The ovum.
What is the smallest eucaryotic cell in the human body?
The sperm. Why did I say eucaryotic?
Which human cells have the longest lifespans?
Neurons
Which human cells are immortal?
HeLa cells.
Which cells have the shortest lifespan?
Neutrophils. They only live about 4 hours.
What cell type is pictured?
Red blood cells
True or False: Erythrocytes have no organelles.
True.
What is the main function of RBCs?
To transport gases (O₂ and CO₂)
How do erythrocytes (RBCs) tranport oxygen and carbon dioxide?
By carrying them in a molecule called hemoglobin.
What is hemolyses?
The cytolyses of red blood cells, often shortened to lyses.
What cell type is indicated?
neutrophil
What are some other names for neutrophils?
Polymorphonuclear leukocytes, PNMs, or microphages are all names for neutrophils the most abundant white blood cells in the human body.
What do we commonly call dead neutrophils?
Pus. Dead neutrophils are the main component of pus. They are the primary immune cells for fighting infections, but they are short-lived. Usually less than 24 hours. When neutrophils die they, along with bacteria and other dead cells, form a purulent exudate at the infection site. Pus within the epidermis is called a pustule. It is an abcess in deeper tissues.
Neutrophils are granulocytes. What are the other two types of granulocytes?
Eosinophils and basophils.
What is this cell called?
Macrophage
What is the name of this cell?
Neuron
What type of connective tissue fiber is this?
Collagen
What type of connective tissue fiber is this?
Elastic. This the Verhoefff Van Giesen stain. (aka VVG, EVG, Elastic stain)
What type of connective tissue fiber is this?
Reticular. This is a Modified Gomori Retic. The previous was a Gordon and Sweet Retic.
Which connective tissue fiber can be easily seen in an H&E stained section.
Collagen.
What is a neuron?
A nerve cell.
What are neuronal processes?
The extensions of axon and dendrites from the cell body.
What is another name for the neuronal body?
The soma.
What size are neurons compared to other cells?
They are larger (from 4-135 microns in diameter).
True or False: Neuronal nuclei have an obvious chromatin pattern.
False: The nuclei of nerve cells are mostly euchromatic with a prominent (and darkly staining nucleolus). Euchromatin is the lightly staining, transcriptionally active form of chromatin.
Where are mast cells found?
Loose connective tissue near vessels as in the lamina propria of the GI tract or near follicules and glands in the skin.
What are the 3 basic shapes of bacteria?
Bacillus (rod), coccus (sperical) and spirillum (spiral)
What shape is this bacteria? Is it Gram positive or negative?
This is Clostridium botulinum (Botulism), a Gram positive drumstick-shaped (bacillus) bacteria.
What shape is this bacteria? Is it Gram positive or negative?
Salmonella typhi (salmonella), a Gram negative bacillus.
What shape is this bacteria? Is it Gram positive or negative?
Clostridium tetani (tetanus), a Gram positive drumstick-shaped (bacillus) bacteria.
What shape is this bacteria? Is it Gram positive or negative?
Streptococcus pneumoniae (pneumonia), a Gram positive diplococcus.
What shape is this bacteria? Is it Gram positive or negative?
Escherichia coli is a Gram negative bacillus.
What does the saying “One night with Venus, a lifetime with Mercury” mean?
Mercury was used to treat syphilis. Shown is a Steiner for spirochetes.
True or False: Lyme disease and syphilis are both caused by spirochetes.
True. Spirochete of Lyme disease is shown. The stain is a Dieterle.
What silver stains are routinely used for spirochetes?
Warthin-Starry, Dieterle, Steiner and Steiner. Shown is a Warthin-Starry for syphilis.
What is different about rickettsia?
These are bacterial parasites that, like viruses, require a host cell to grow. They are transmitted to humans by ticks, lice, mites and fleas.
What diseases do rickettsia cause?
Trench fever, Rocky Mountain Spotted Fever and Typhus.
What is the difference between the Typhoid and Typhus?
They are caused by different bacteria. Typhoid Fever is caused by salmonella typhi and Typhus is caused by rickettsia.
True or False: The pathologist Howard Taylor Ricketts died of a rickettsia disease.
Yes, he was studying the bacteria.
True or False: Rickets is caused by rickettsia.
False. Rickets is caused by a Vitamin D deficiency.
What are hyphae?
The threadlike branching filaments that make up fungi.
Is a hypha a cell?
A hypha is one or more tubular cells. They are either septate (separated by cell walls) or coenocytic (no distinct cell separation). They can be multinucleate.
True or False: Yeast and molds are types of fungi.
True. Yeasts are unicellular (psuedohyphae) and molds are multicellular (hyphae).
Why is tissue for brain stains cut thicker?
Because neurons are bigger cells with diagnostically important small elements, such as Nissl Substance.
What are the components of blood?
Red blood cells, white blood cells (leukocytes), platelets, and plasma.
What are the formed elements of blood?
Red blood cells, white blood cells, and platelets. Everything but the plasma.
What are leukocytes?
White blood cells.
Name some different types of leukocytes.
Basophil, eosinophil, neutrophil, monocyte, macrophage, natural killer cell, T lymphocyte, B lymphocyte, plasma cell.
What is another name for platelets?
Thrombocytes. Cell fragments that aid in clotting.
Where are blood cells formed?
Bone marrow.
Where do plasma cells come from?
They differentiate from B cells (lymphocytes).
What cell produces and secretes antibodies?
The plasma cell.
True or False: There is only 1 type of B cell (or B lymphocyte).
False. There are many types of B lymphocytes. The 2 differentiated types of B cells are Plasma cells and Memory B cells.
True or False: Both plasma cells and memory B cells are specific to an antigen.
True. When a mature B cell encounters an antigen and clones itself, some clones differentiate into plasma cells and some into memory B cells, both specific to the initially encountered antigen.
Horseshoe crabs have blue blood because oxygen is transported through vessels by a copper containing protein called hemocyanin. Why do humans have red blood?
Humans have red blood because RBCs use an iron containing protein called hemoglobin to transport oxygen. Bright red blood is oxygenated, dark red blood is deoxygenated.
If Schwann cells insulate axons by forming myelin sheaths in the PNS, how are neurons in the CNS protected?
By myelin sheaths. They are formed by ogliodendrocytes in the CNS.
What do the nuclear matrix, the extracellular matrix and the cytoskeleton have in common?
They form the basic structure and shape of cells and tissues.
What are the 3 parts of the cytoskeleton?
The microfilaments, the intermediate filaments, and the microtubules.
The cytoskeleton is made of proteins. If microfilaments are made of actin and microtubules are made of tubulin; what are intermediate filaments made of?
Keratin. The protein keratin forms hair and nails and the stratum corneum layer of the skin. This is called keratinization (cornification) of the skin. Cytokeratin makes up the intermediate filaments of the cytoskeletons of epithelial cells.
True or False: Muscle is considered an organ.
True. Every muscle contains connective, nerve and vascular tissue as well as muscle tissue.
What distinguishes skeletal muscle from smooth and cardiac muscle?
Cardiac and smooth muscle are involuntary. Skeletal muscle is the only voluntary muscle it attaches to bones with tendons. The fibers are striated with multiple periperal nuclei.
Skeletal muscle is covered with epimysium and under that are several fascicles wrapped in what?
Perimysium.
So, if muscle at the organ level is wrapped in epimysium and within that are fascicles wrapped in perimysium, what is the next level?
Going from largest to smallest the next level would be muscle fibers wrapped in endomysium.
What is another name for muscle fiber?
Myocyte, or muscle cell.
What is the cell membrane of the muscle fiber called?
The sarcolemma.
What proteins make up the myofibrils of the muscle cell (or fiber)?
Actin, Myosin, and titin.
What is the cytoplasm of a muscle cell called?
The sarcoplasm.
True or False: Due to high energy needs, muscle cells contain more mitochondria than other body cells.
True. Muscle and nerve cells need to produce more ATP and therefore have more mitochondria than other somatic cells.
True or False: In eukaryotic cells genetic material is found only in the protected nucleus.
False. Eukaryotic cells have organelles; and one of these organelles, the mitochondrion, has its own DNA.
True or False: Mitochondria have their own genetic material, but cannot synthesize protein.
False. Mitochondria can synthesize their own protein, as well as, break down proteins, fats and carbohydrates.
True or False: The mitochondria are the only eukaryotic organelle that has a double membrane.
True.
True or False: Because of their history as separate organisms, mitochondria perform their duties independently of other organelles including other mitochondria.
Absolutely False. Mitochondria often fuse together to form chains and their interaction with other organelles is crucial for homeostasis. They form MOCS (mitochondrial organelle contact sites) to echange signals and molecules such as calcium. They can signal apoptosis, for example. Defects in the mitochondrion, itself, or its MOCS have been associated with many disease states.
What are the 4 main tissue types?
Epithelial, Connective, Muscle, Nerve.
What is the function of epithelial tissue?
It lines and protects passageways and controls movements (secretion, absorption) across those surfaces. It also provides sensory reception.
What is the apical surface of epithelial cells?
The surface thst faces the external environment (lumen). This surface might be covered with cilia or microvilli.
What is the basal surface of epithelial cells?
The part next to the basement membrane.
True or False: Epithelial cells comprise mucous, serous, and cutaneous membranes.
True. The mucosa is the mucous membrane lining body cavities and producing mucus. Serous mebranes produce serous fluid between surfaces such as the peritoneum, pericardium and pleura. The cutaneous mebrane is covered with keratinized cells, like the skin.
