Chapter 3: Cell Structure and Function Flashcards
What are the 4 processes of life?
Growth, Reproduction, Responsiveness, Metabolism
Compare/describe the characteristics of life. (hint: G, R, R, M, C)
Growth: Increases in size.
Reproduction: Increases in number.
Responsiveness: ability to react with environmental stimuli
Metabolism: Controlled chemical reactions of organisms.
Cellular structure: Membrane-bound structure capable of all of the above functions.
Compare the processes/characteristics of life/whether or not they occur in bacteria, archaea, and eukaryotes.
Growth: occurs in all Reproduction: occurs in all Responsiveness: occurs in all Metabolism: occurs in all Cellular structure: present in all
Compare the processes/characteristics of life in relation to viruses. (hint: G,R,R,M,C)
- Growth: Growth does not occur
- Reproduction:Host cell replicates the virus
- Responsiveness:Reaction in host cells seen in some viruses.
- Metabolism:viruses use host cell metabolism.
- Cellular structure: viruses lack cytoplasmic membrane or cellular structure.
What organisms are Prokaryotes v. Eukaryotes composed of?
Prokaryotes: Bacteria and archaea
Eukaryotes: Animals, Algae, Fungi, Protozoa, and plants
Describe whether Prokaryotes v. Eukaryotes have a nucleus.
Prokaryotes: Lack nucleus
Eukaryotes: Have nucleus
Describe the internal structure of Prokaryotes v. Eukaryotes.
Prokaryotes: Lack various internal structures, bound with phospholipid membranes.
Eukaryotes: Have internal membrane bound organelles.
Compare Prokaryotes v. Eukaryotes in size and complexity
P: smaller-typically 1 micrometer in dm or smaller, simple structure
E: larger-10-100 micrometers in dm, complex structure
What is the external gelatinous, sticky substance surrounding the bacterial cell?
Glycocalyces
What components is the Glycocalyces composed of?
polysaccharides, polypeptides, or both
What are the two types of glycocalyces?
capsule, slime layer
Describe the slime layer type of the glycocalyces surrounding the bacterial cell.
Loosely attached to cell surface, Water soluble, Sticky layer allows prokaryotes to attach to surfaces
Describe the capsule type of the glycocalyces surrounding the bacterial cell.
Composed of organized repeating units of organic chemicals, Firmly attached to cell surface, May prevent bacteria from being recognized by host
What are flagella responsible for?What are their function?
Movement. Propels bacterium through environment.
Are flagella present on all bacteria?
No
Describe components of flagella structure.
Composed of filament, hook, and basal body.
What does the basal body component of the flagella do?
Anchors the filament and hooks to cell wall,
Flagella move in what direction? Move in response to what?
- Counterclockwise or clockwise
- Move in response to stimuli (run, tumble)
What are frimbriae?
Sticky, bristlelike projections
What are the function of fimbriae?
Used by bacteria to adhere to one another and to substances in the environment.
Are fimbriae or flagella shorter?
Fimbriae
Pili is a special type of what?
Fimbriae
Compare length between pili vs. flagella and fimbriae
Pili is longer then fimbriae but shorter than flagella.
Bacteria typically have one or two of these organelles per cell.
Pili
What type of special function do pilli have in relation to DNA?
Transfer DNA from one cell to another
What is the function of the cell wall?
To Provide structure and shape and protect from osmotic forces. Assist some cells in attaching to other cells or in resisting antimicrobial drugs.
What are the two basic types of bacterial cell walls scientists describe?
Gram positive and Gram negative bacteria
Compare the layer of peptidoglycan in gram neg v gram pos bacteria.
Gram neg: Only a thin layer of peptidoglycan Gram pos: relatively thick
Compare the components of Gram neg v Gram positive bacteria.
Gram negative: Bilayer membrane outside the peptidoglycan contains phospholipids, proteins, and lipopolysaccharides (LPS). Gram positive: contain unique polyalcohols called teichoic acids.
Name and label the cell below gloing clockwise starting with the purple box.
- Inclusions
- Flagellum
- Cytoplasmic Membrane
- Glycocalyx
- Nucleoid
- Cytoplasm
- Ribosome
What color does Gram neg v Gram pos stain?
Gram positive: Appears pruple
Gram negative: Appears pink
What may the bacterial cytoplasmic membrane also be referred to as?
Cell membrane
The structure of the bacterial cytoplasmic membrane is referred to as what?
A phospholipid bilayer
What is the bacterial cystoplasmic membrane composed of?
Phospholipids and associated proteins
Name the associated proteins that the bacterial cytoplasmic membrane is composed of.
Integral and peripheral proteins
The phospholipid molecules that compose the phospholipid bilayer in the bacterial cytoplasmic membrane are considered to be what?
Bipolar
Describe the bipolar nature of the phospholipid molecule located in the phospholipid bilayer of the bacterial cytoplasmic membrane.
The phosphate containing heads of eache phospholipid molecule are hydrophilic, while the tails are hydrophobic.
What model describes our current understanding of the membrane structure?
Fluid Mosaic model
Describe the function of the Cytoplasmic bacterial Membrane. (hint, 6)
- Energy storage
- Harvest light energy in photosynthetic bacteria
- Selectively permeable
- Naturally impermeable to most substances
- Proteins allow substances to cross membrane
- Maintain concentration and electrical gradient
The difference in concentration of a chemical on the two sides of a membrane is called what?
Its concentration gradient
A greater concentration of what charged proteins exist inside the bacterial cytoplasmic membrane? Exist outside?
Inside: Negatively charged proteins
Oustide: positively charged
Researcher have developed a special staining procedure called the_________to stain Gram ________ cells. What is another name for these types of cells?
Acid fast stain, positive, acid-fast bacteria
Mycolic acid helps cells with Gram-______cells survive what? What is Mycolic acid?
Positive
dessication
A waxy lipid
The net movement of a chemical down its concentration gradient-from higher to lower area of concentration is what type of passive process?
Diffusion
The electrochemical gradient provides the source of energy in what type of processes across the bactrial cytoplasmic membrane?
Passive
Which passive process in the bacterial cell membrane cause integral proteins to facilitate certain molecules to diffuse down their concentration gradients into or out of the cell by providing a pathway for diffusion?
Facilitated Diffusion
What is the name of the passive process given to the diffusion of water across a superimpermeable membrane?
Osmosis
What is a semipermeable membrane?
A membrane that is permeable to water molecules but not to most solutes present (such as proteins, salts, glucose, or amino acids).
What is the function of active transport?
ATP dependent carrier proteins bring substances into a cell (i.e. Na+, K+, Ca2+, H+, Cl-)
Name the types of active processes
Active Transport, Group translocation
The active transport proteins in active transport process are referred to as what? Why?
Gated channels or ports
Because they are controlled
What happens during Group Translocation? Does this Active process happen in all bacteria?
The substance being actively transported across the membrane is chemically changed during transport.
No.
Which active process are uniports, antiports, and symports involved in in the bacterial crytoplasmic membrane? Explain the difference between the three.
Active transport
Uniport-When onw substance is trasnported at a time.
Antiport- Simultaenously transport two chemicals in oposite directions.
Symport-When two substances move together in the same direction aross the membrane by means of a single carrier protein.
Name 3 components of the cytosol portion of the cytoplasm of bacteria
- Liquid portion of cytoplasm
- Mostly water
- Contains cell’s DNA in region called the nucleoid
What does the inclusion function as in bacteria?
structure that may include reserve deposits of chemicals
Name four functions of endospores
- Unique structures produced by some bacteria
- Defensive strategy against unfavorable conditions
- Vegetative cells transform into endospores when mult nutrients are limited
- Resistant to extreme conditions suck as heat, radiation, and chemicals
What is the function of ribosomes? What are riposomes composed of?
- Sites of protein synthesis
- polypeptides and ribosomal RNA
What roles does the cytoskeleton play in the cell? (hint, 4)
cell division, cell shape, segregate DNA molecules, Move through the environment
Name the external structures of the flagella (hint, 4 )
- Glycocalyces
- Flagella
- Fimbriae and hami
Which external strtucture in archae functions in the formation of biofilms?
Glycocalyces
What are some differences between archaec flagella and bacterial flagella?**
What is the function of hami?
To attach arachaea to surfaces
Do Arachea cell walls contain peptidoglycan?
No
What makes up archaea?
specialized polysaccharides and proteins
How is the archaeal cytoplasm different from the bacterial cytoplasm?
- Different ribosomal proteins
- Different metabolic enzymes to make RNA
- Gentic code more similar to eukaryotes
Compare how the archeal cytoplasm is similar to the bacterial cytoplasm.
- 70S ribosomes
- fibrous cytoskeleton
- circular DNA
Compare pili in archaea v bacteria
- archaea: none discovered
- bacteria:present in somem proteinaceous, used in bacterial exchange of DNA.
Compare the cytoplasmic membrane in archaea v bacteria
Archaea: membrane lipids made with ether linkages, some have single lipid layer.
Bacteria: phospholipid bilayer
Describe the functions of the structure Glycocalyces in Eukaryotes
Not as organized as prokaryotic capsules
Help anchor animal cells to each other
Stengthen cell surface
Provide protection against dehydration
Function in cell-to-cell recognition and communication
Which Eukaryotes have cell walls?
Fungi, algae, plants, and some protozoa have cell walls.
What are fungal cell walls composed of?
cellulose, chitin, and/or glucomannan
What are algae cell walls composed of?
polysaccharides
Do eukaryotic cells have a cytoplasmic membrane?
Yes
What are the active transport processes found only in eukaryotes?
Endocytosis and Exocytosis
What happens during Endocytosis? What two processes occur within endocytosis?
Substances are surrounded by pseudopods and brought into the cell.
Phagocytosis and pinocytosis.
What is the difference between phagoctosis and pinocytosis in endocytosis?
Phagocytosis involved solid substances.
Pinocytosis involves liquids.
Which active transport process in eukaryotes can be described as when vesicles containing substances are fused with cytoplasmic membrane, their contents to the outside?
Exocytosis
Describe the characteristics of the structure and arrangement of flagella in Eukaryotes (hint, 4)
- Within the cytoplasmic membrane
- Shaft composed of tubulin arranged to form microtubules
- Filaments anchored to cell by basal body; no hook
- May be single or multiple; generally found at one pole of cell
What is the function of flagella in Eukaryotes?
Do not rotate but undulate rhythmically
Describe the characteristics of cilia (hint, 3)
- Shorter and more numerous than flagella
- Coordinated beating of cilia propels cells trhough environment
- Also used to move substances past the surface of the cell.
What role do centrioles play?
Play a role in mitosis, cytokinesis, and formation of flagella and cilia.
What role does the centrosome play in eukaryotes?
The centrosome is the region of cytoplasm where centrioles are found.
Name some characteristics of the nucleus (hint, 5)
- Often largest organelle in cell
- Contains most of the cell’s DNA
- Semiliquid portion called nucleoplasm (contains chromatin)
- RNA synthesized in nucleoli presnt in nucleoplasm
- surrounded by nuclear envelope (contains nuclear pores)
What are the nonmembranous organelles of eukaryotes?
ribosomes, cytoskeleton, centrosome
What are the membranous organelles of eukaryotes? (hint, 8)
- Nucleaus
- Endoplasmic Reticulum
- Golgi bodies
- Lyosomes
- Peroxisomes
- Vacuoles
- Vesicles
- mitochondria
- Cholorplasts
Which membranous organelle of Eukaryotes is continuous with the outer membrane of the nuclear envelope and structured in a netlike arrangment of flattened hollow tubules?
- Endoplasmic reticulum
The Endoplasmic Reticulum functions as a ____ system and is found in what two foms?
- Transport
- Smoothe endoplasmic Reticulum, Rough Endoplasmic Reticulum
What role does smoothe endoplasmic reitculum play?
Plays a role in Lipid synthesis as well as transport.
Why is the rough endoplsmic reticulum rough?
Because ribosomes adhere to its outer surface
Name the characteristics of the Golgi body. (hint, 2)
- Receives, processes, and packages, large molecules for export from cell.
- Packages molecules in secretory vesicles that fuse with the cytoplasmic membrane.
What is the structure/composition of the Golgi body?
Composed of flattened hollow sacs surrounded by phospholipid bilayer
Is the golgi body present in all eukaryotic cells?
No
What is the function of lysosomes, peroxisomes, vacuoles, and vesicles?
To store and transfer chemicals within eukaryotic cells
Lyosomes contain what kind of enzymes? What do these enzymes do?
Catabolic
Damage the cell if they are released from their packaging into the cytosol.
Peroxisomes contain enzymes that do what?
Degrade poisonous wastes
Name some characteristics of Mitochondria (hint, 3)
- Have two membranes composed of phospholipid bilayer
- Produce most of cell’s ATP
- Interior matrix contains 70S ribosomes and circular molecule of DNA
What are light harvesting structures found in photosynthetic eukaryotes?
Choloroplasts
Choloroplasts use ____ energy to produce ________ and form __________from carbon dioxide.
Light
ATP
sugar
What kind of ribosomes do choloplasts have?
70S
What does the Endosymbiotic Theory suggest?
Eukaryotes formed from the union of small aerobic prokaryotes with larger anaerobic prokaryotes.
What is the composition/structure of chloroplasts?
Have two phospholipid bilayer membranes and DNA.
