Flashcards in Cell Biology Deck (79):
What is cell biology also known as?
A cell is the most basic working unit of _______
New cells only arise how?
From existing cells, by cell division
What are the two basic types of microscopy?
Light microscopy, electron microscopy
What type of microscopy is dependent on on transmitted light to illuminate the biological sample of interest?
What type of light microscopy is the conventional form of light microscopy, using visible light as the source?
Which type of microscopy depends on ultraviolet light to illuminate the specimen against a black background?
What type of microscopy depends on an electron beam to bombard the specimen (which has normally been killed by chemical fixation prior to examination)?
What is the key advantage of electron microscopy over light microscopy?
A greater resolution (by at least 100x)
When an electron beam passes through an ultrathin, carefully prepared section of the specimen to reveal the contents of the cell which is "stained" with heavy metal it is __________
Transmission Electron Microscopy (TEM)
When a specimen remains intact, but gets coated with a thin film of heavy metal so that the beam is deflected off the contoured surface to yield a 3-d image it's called __________
Scanning Electron Microscopy (SEM)
What separates the cytoplasm of the cell from the cell exterior?
the cell (plasma) membrane
What accumulates as a protective matrix along the membrane's outer surface?
The cytoskeleton in made of microfilaments of a protein called _____
Complexity, ex. possession of more types of organelles, is more common in _____ ____
Which cells have no membrane bound nucleus?
Which cells are small and unicellular or occasionally colonial? (NEVER multicellular)
What is composed of a phospholipid bilayer with other components like protein channels that governs entry and exit of materials in the cell?
The cell membrane
The cell membrane represents the major, and usually only, membrane system of a ________ cell.
What does the cytoplasm of a prokaryotic cell contain?
a nucleoid region (DNA), and ribosomes
Prokaryotic cells rarely possess a vacuole lined by a membrane called ______
Tonoplasts help to retain ___ _______
Prokaryotes also have external features like a cell wall, glycolayx, pili, and ________
The cell wall protects the cell membrane and _______
What is secreted externally to the cell wall as a slime layer or capsule?
The glycocalyx enables the cell to adhere to substrates or to eachother (i.e. to form a ________)
Short abundant extensions that assist in attachment to surfaces and even other cells are called ______
Pili (pilus singular)
What part of the cell is used for locomotion and possess proteins called microtubules which permit a flexible whip-like action?
Flagella (singular flagellum)
Which cells can be singular, colonial, or commonly multi-cellular?
Eukarya contains what four groups?
Fungi, Animalia, Plantae, Protista (often unicellular)
Eukaryotes all have what?
A membrane bound nucleus
What is typically the largest organelle in a eukaryotic cell representing 10-20% of it's volume?
Two phospholipd bilayers, an inner and outer, which enclose a perinuclear space surrounding the nulceus of a eukaryotic cell comprise the _________
What is the semi-fluid substance filled with chromatin inside the nucleus?
What stores, protects, organizes, and expresses most of the cell's hereditary information?
Each nucleus may have one or more _________
What consists of two subunits of rRNA and proteins?
Inside the cytoplasm, is the ___________ system.
What includes vacuoles, lysosomes, secretory vesicles, Golgi apparatus, endoplasmic reticulum, and even the cell membrane?
The endomembrane system
What has an extensive, membranous network of flattened cisternae which are narrow tubules that contain fluid in the lumen?
The Endoplasmic reticulum
The rough endoplasmic reticulum is characterized by ________ attached to the cisterna's outer surface.
What happens in the smooth ER?
synthesis of lipids and production of hormones.
The synthesis of glycoproteins by adding a carbohydrate is called _________
What happens in the rough ER?
Glycosylation and formation and sorting of proteins
What serves as distribution centre for proteins?
When a secretory vesicle fuses with the plasma membrane, releasing the vesicle contents to the cell exterior it is called ___________
The golgi complex can perform what three functions?
glycosylation, protein sorting, and secretion
If materials from outside the cell were incorporated into the vesicles it would be called __________
Pinocytosis is when cells "sample" solutes in the external environment that ______ nutrients
Lysosomes are membrane-bound organelles of _________ cells
Lysosomes contain hydrolases which function optimally in their ____ environment
A defective organelle in the cytoplasm will become surrounded by a membrane and form an _________
an autophagosome will fuse with lysosomes and they will convert it to subunits for ________
When the vesicle with cargo pinches off from the cell membrane and enters the cell's cytoplasm where this endocytotic vesicle fuses with a lysosome and the cargo is broken down into simpler compounds which are released to the cytoplasm it is called ____________
What is it called when a large membrane-bound vesicle surrounds and engulfs a fairly large item (ex. bacterium), proceeds to fuse with lysosome whose acid hydrolases dismantle the bacterial cell?
A fluid-filled sac is called a _______
What is the single membrane that lines the vacuole?
What type of vacuoles are present in many plant cells and take up much of the volume?
A central vacuole provides what two things?
Storage, Turgor pressure
What type of vacuole is present in many protists, gradually increasing in volume and eventually expelling its aqueous contents?
Food vacuoles have food for eventual _______
Cytoskeleton maintains cell's ______ and organelle _______, even a cell's own motility.
What size is the diameter of microfilaments?
Diameter of intermediate filaments?
Diameter of microtubules?
Microfilaments are assembled from what protein?
What are the functions of microfilaments?
Muscle contraction, movement of pseudopods, separation of cytoplasm during cell division, cytoplasmic streaming
Intermediate filaments only occur in _________ organisms
Microtubules are a major part of what apparatus at cell division?
Which motor proteins have intimate association with cytoskeleton?
What is short but numerous and produces beating movements leading to locomotion or circulation of fluids and debris over the cell surface?
Mitochondria and plastids are both what?
Semi-autonomous organelles (have their own DNA)
Both mitochondria and plastids have a _______ membrane
If it has a mitochondria, nucleus, nucleolus, and nuclear envelope, it is what type of cell?
What plastids have chlorophyll? Grana, And thylakoids in each granum surrounding a lumen?
What plastids have pigment crystals?
Which plastids are starchy and colourless?
The semi-autonomous, energy-transforming organelles of eukaryotic cells, namely mitochondria and chloroplasts, may have descended from free-living prokaryotic cells is the Theory of what?