Jessicas Chapter 4-5 Notecards Flashcards
Using the term surface-area-to-volume-ration, explain why the vast majority of cells are small?
A cell needs a surface that is large enough to let nutrients in and let accumulating toxins out.( determines the size) Large cells would have to much going on inside compared to the surface area exchange.
What are the three statements that make up Cell Theory?
- All organisms are composed of cells 2. Cells are the basic unit of structure and function in organisms 3. Cells come only from pre existing cells (self-reproducing)
What shape is bacillus?
Rod-shaped
What is the shape of coccus?
Spherical
What is the shape of spirochete?
long, twisted rod-shapes
What are the three parts of the cell envelope?
Inside-outside plasma membrane, cell wall, and glycocalyx
Describe the first part of cell envelope.
Plasma membrane- regulates entrance and exit of substances to and from the cytoplasm (water based matrix inside the cell).
Describe the second part of cell envelope.
Cell wall- made of peptidoglycan and provides structure that is strong enough to resist cell swelling when water enters the cell.
The third part of cell envelope.
Glycocalyx(carbohydrate)-helps keep water in the cell, and an organized glycocalyx called a capsule protects some bacteria from a host immune system.
What is the difference between flagella and fimbriae?
Flagella- comparatively long appendages
Fimbriae- comparatively short appendages
Describe the function of a conjugation pili.
The appendage is a rigid tube used to pass DNA from cell to cell.
How do bacteria reproduce?
Split into two cells by binary fission
Is the conjugation pili involved in bacterial reproduction?
No. While it does pass on genetic info to other bacteria, it is not for the purpose of replication
Where is genetic information of prokaryote found in the cell?
In the cytoplasm. The Dna is coiled and forms a nucleoid which is not membrane bound
Describe the bacterial chromosome.
It’s DNA of a single-circular molecule. It forms the nucleiod.
How is bacterial chromosome different from a plasmid?
Bacterial chromosome- molecule of circular DNA
Plasmid-cell that can replicate chromosomes, like bacterial chromosomes
Are Cyanobacteria producers or consumers? How can you tell?
Producers because they are capable of photosynthesis like eukaryotic plants.
What do cyanobacteria use thylakoid membranes for?
To convert energy of the sun to energy containing bonds in organic molecules.
What two things are found in thylakoid membranes?
Chlorophyll and other pigments
Describe the changes that would have produced a membrane-bound nucleus. (Eukaryotic)
Eukaryotic cells were prokaryotes until they evolved from the invagination of the plasma membrane.
Describe the endosymbiotic theory of the changes that would produce a photosynthetic eukaryotic cell.
Eukaryotic cell engulfed cyanobacteria and instead of killing them, began using the products of cellular respiration for their metabolism.
Describe the endosymbiotic theory of the changes that would produce a eukaryotic cell able to use sugar and oxygen to create energy rich molecules (ATP).
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How are ribosomes different in prokaryotes compared to eukaryotes? Explain how this difference supports the endosymbiotic theory
Eukaryotes have larger ribosomes and found in the nucleolus in the nucleus where as prokaryotes are smaller and can be found in the cytoplasm
Chloroplasts and mitochondria are double membrane-bound organelles. Explain how this supports the endosymbiotic theory
Chloroplasts are the same size as cyanobacteria and mitochondria is the same size as heterotrophic bacteria. Both have a double membrane: one layer from the eukaryotes plasma membrane and one layer from the bacterias plasma membrane. Both have ribosomes that are the same size as bacterial ribosomes.
Characteristics and function in an eukaryotic cell: nucleus.
- Command center of the cell.
- large organelle
- nucleoplasm is the semi fluid matrix in the nucleus
- contains chromatin( nucleic acid DNA with proteins to organize)
Characteristics and function in an eukaryotic cell: nucleolus
Produces subunits of ribosomes
Characteristics and function in an eukaryotic cell: ribosomes
- Protein synthesis occurs in the cytoplasm, so ribosomes have to move through to do their jobs
- large and small subunits constructed in the nucleolus in the nucleus
- made of rRNA and some proteins
Characteristics and function in an eukaryotic cell: rough er
Studded with ribosomes that synthesize proteins
Characteristics and function in an eukaryotic cell: smooth er
Lacks ribosomes, synthesizes lipid molecules
Characteristics and function in an eukaryotic cell: Golgi apparatus
- Processes,packages, and secretes modified proteins
- Transports to the plasma membrane and other places in the cytoplasm like lysosomes.
- 3-20 flattened saccules
Characteristics and function in an eukaryotic cell: lysosomes.
- Vesicles that bud off the trans face of the Golgi apparatus.
- It assists in the digestion of cellular materials.
- Lysosomes can fuse with vesicles containing material from outside the cell and digest the material.
Characteristics and function in an eukaryotic cell: peroxisomes(micro bodies)
-Peroxisomes break down hydrogen period ideal it won’t damage the cell.
-Liver cells that need to convert fatty acid to glucose for cell
Plants: germinating seeds need to convert fatty acids to glucose for cellular reparation
Characteristics and function in an eukaryotic cell: mitochondria
Organelle that carries out cellular respiration, and produces ATP.
Double membrane:
- matrix: inside the inner membrane that has its own ribosomes and DNA
- inner membrane is folded into cristae
Characteristics and function in an eukaryotic cell: centrosomes
Microtubule organizing center that contains a pair of centrioles
What are two additional organelles found in a plant cell? What are their function and characteristics?
Central vacuole: filled with a water solution call cell sap. It takes up 90% of cytoplasmic space. And provides support and structure to the plant cell.
Chloroplast: contains the membranes, enzymes, and pigments for photosynthesis. It has a double membrane. It has thylakoids that are disk shape. Grana is a stacks of thylakoids and stroma is the water solution inside the chloroplast.
Identify all organelles of a eukaryotic cell.
Cytoskeleton Centrioles- centrosomes Vesicle Lysosomes Nucleus ER Golgi apparatus Ribosomes Mitochondria
The cytoskeleton is made up of what three types of filaments? Which is the thickest and the thinnest?
- Actin filaments: thinnest
- Intermediate filaments : middle sized
- Microtubules: largest
What protein is the subunit used to build microtubules?
Tubulin is the subunit
Which filament creates centrioles when arranged in a 9 + 0 pattern?
Basel body is made of nine groups of three microtubules.
Which filament created flagella when advanced in a 9+2 pattern?
Nine groups of two microtubules
How is the motion of prokaryotic flagella different from the motion of eukaryotic flagella?
Prokaryote flagella- small/simple structure made up of protein flagellum (proton driven) (rotatory movement)
Eukaryotic flagella- larger and complex structure, tubulin microtubules, bending movement, ATP driven.
How is basal body associated with flagellum?
Can’t find
Which filaments can dynamically rearrange to create movement at the plasma membrane of amoeba?
Actin filaments
Name two types of organic molecules that are found embedded or peripheral in the phospholipid of the plasma membrane.
Embedded membrane proteins
- integral membrane proteins: that can span the bilayer from outer to inner layer
- peripheral proteins: can be anchored in just the inner layer
Use the word a philatelic molecule to describe a phospholipid including the terms hydrophilic and hydrophobic.
Phosphate head is hydrophilic
fatty acid tail is hydrophobic
What does it mean to say a protein is embedded in the phospholipid bilayer?
Can’t move from the inner/outer layer to the outer/inner layer
What does it mean to say a protein is peripheral in the phospholipid bilayer?
Proteins that can be anchored in just the inner layer.
Do peripheral proteins face the inner or outside or the cell?
Inner
When there is a carbohydrate bonded to a membrane phospholipid, the molecule is called a ___________?
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When there is a carbohydrate bonded to a membrane integral protein, the molecule is called_____?
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Using hydrophobic, explain why integral and peripheral proteins stay anchored in the phospholipid bilayer and don’t move into the space outside or inside the cell
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Using hydrophilic, explain why integral and peripheral proteins stay anchored in the phospholipid bilayer and don’t move into the space outside or inside the cell
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Explain the fluid mosaic model
- Phospholipids can move in their layer of the bilayer
- macromolecules that are hydrophobic will stay embedded in the membrane but can move around
- molecules embedded in the membrane can also be anchored by interactions with the structure in the cytoplasm or outside the cell
The plasma membrane is asymmetric. What does that mean?
There are two layers but they are not exactly the same
What is the function of the integral membrane proteins: channel proteins
Passing molecules through the membrane. They form a channel that allows a substance to simply move from one side to the other.
What is the function of the integral membrane proteins: carrier proteins
Passing molecules through the membrane. They recurve a substance and change their shape, this change moves the substance across the membrane.
What is the function of the integral membrane proteins: cell recognition proteins
They are glycoproteins that help the body recognize when it is being invaded by pathogens, so an immune response can occur.
What is the function of the integral membrane proteins: receptor proteins
Have a shape that allows specific molecules to bind to it. The binding of the molecule allows the proteins to change shape to bring cellular response.
What is the function of the integral membrane proteins: enzymatic proteins
Carry out metabolic reactions, without these enzymes, a cell would never be able to perform the chemical reactions needed to maintain its metabolism.
What is the function of the integral membrane proteins: junction proteins
Form varies junctions between animal cells. Signals molecules that pass through gap junctions allow the cilia of cells to beat in unison
Do charged molecules move easily into or out of a cell? Explain
No because they are chemically incompatible with the center of the membrane and require a lot of energy to drive their transport
Do small no charged molecules move easily into or out of a cell? Explain
Yes because they are able to slip between hydrophilic heads of the phospholipids and pass through the hydrophobic tails of the membrane
Do large macromolecules move easily into or out of a cell? Explain.
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Name the channel protein that allows water to move freely into and out of the cell.
Hydrophobic molecules ( small no polar molecules)
Define diffusion.
Molecules and ions move from high to low concentration
Define osmosis.
Diffusion of water
What does it mean for a molecule to move down it’d concentration gradient? How does it looks if there is no membrane? How does it look if there is a selectively permeable membrane present?
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How does water move through a selectively permeable membrane in an isotonic solution?
Water will move into the cell through aquaporins and out of the cell through aquaporins equally so the amount of water in the cell will stay the same.
How does water move through a selectively permeable membrane in a hypotonic solution?
Water will move into the cell through aquaporins down its concentration gradient so the amount if water in the cell will increase and rage cell will swell.
How does water move through a selectively permeable membrane in a hypertonic solution?
Water will move out of the cell through aquaporins down its concentration gradient so the amount of water in the cell will decrease and the cell will shrink.
A cell will shrink when placed in a _______ solution.
Hypertonic
A cell will swell when placed in a ________ solution.
Hypotonic
A cell will stay the same size when placed in a ______ solution.
Isotonic
How does a plant cell wall protect the cell in a hypotonic solution?
The cell wall doesn’t allow for the water to bust the cell.
Explain facilitated transport using carrier proteins and concentration proteins.
Carrier protein: they change their shape as the process of allowing molecules to pass into or out of the cell
If a molecule is moving didn’t its concentration gradient, no cellular energy needs to be used
If a molecule is moving against its concentration ( low to high concentration) then cellular energy is used.
What process does not require energy in the form of ATP?
Facilitated transport
What process requires energy in the form of ATP?
Active or bulk transport
When energy in the form of ATP is required, it is called _____ transport.
Bulk or active transport
What are the details of a sodium potassium pump?
Moves 3Na+ ions out of the ell and moves 2 K+ molecules into the cell against their concentration gradient
Example of active transport and us s a lot of the ATP created by cellular respiration in mitochondria.
What is exocytosis?
Bulk transport out of the cell
How are substances outside the cell moved inside the cell?
Endocytosis
What is the difference between phagocytosis and pinocytosis?
Phagocytosis: endocytosis of large particles like food or cellular pinocytosis: Endocytosis of a solution ( solvent + solute)
Why is receptor mediated endocytosis sometimes more specific than other types of endocytosis?
- It integral membrane proteins that use their shape and charge to match closely and bind specific molecules
- only correct molecule is transported into the cell
What are the types of organic molecules that create the extracellular matrix?
- mesh work of proteins and polysaccharides
- collagen and elastin are important proteins
- fibronectin is an important glycoprotein
Desmosomes create _______ junctions.
Adhesion
________ junctions hold plasma membranes so close together that molecules can’t pass between adjacent cells.
Tight
______________ junctions create channels that allow molecules to move from the cytoplasm of one cell into the cytoplasm of the adjacent cell.
Gap
What is the difference between gap junctions between animal cells and plasmodesmata between plant cells?
Gap- are connections between adjacent cells that allow cells to communicate (channels)
Plasmadesmata- channels between adjacent cells that are lined with plasma membrane (plasma membrane and cell walls)
