Chapter 6: A Tour of the Cell Flashcards
Ratio between the size of an image produced by a microscope and it’s actual size
Magnification
Ability to observe two adjacent objects as distinct from one a other
Resolution
Shorter wavelength of light provides greater resolution
The two groups of microscopes based on source of illumination
Light microscope (resolution 200 nm)
Electron (resolution 2nm)
Two locations ribosomes carry out protein synthesis
Rough er and cytosol
Free ribosomes- in cytoplasm for the proteins used in the cytoplasm
Bound ribosomes- rough er, membrane proteins are made here
Small and large components made in the nucleus. Come out _________
Separately
ER is an extension of the ________
Nuclear envelope
What are the folds called on both ER?
Cisterne
What does the endomembrane system include ?
- nuclear envelope
- endoplasmic reticulum
- golgi apparatus
- lysosomes
- vacuoles
- plasma membrane
Functions of smooth er?
- synthesis liquids
- metabolize carbohydrates
- store calcium
- detoxify drugs and poisons
Functions of the rough er
Has bound ribosomes
- produces protein membranes which at distributed by transport vesicles (secretory proteins/most glycoproteins)
- membrane factory for cell
What is the membrane factory for the cell?
Rough er
The golgi Consists of flattened membranous sacs called __________
What are the two faces called?
Cisternae
Cis face (forming) Trans face (maturing)
Most subcellular structures, or organelles are too small to be seen by a light microscope. True or false?
True
A type of light microscope that allows living cells to examined in their natural state?
I’m transparent specimens
Phase contrast microscopes
Electron microscopes use __________ rather than glass lenses to focus the beam
Electromagnets
The two most common types of electron microscopes
Transmission TEM- focuses electrons through a specimen
Used to mainly to study internal surface of cells***
Scanning SEM-focuses a beam of electrons into the SURFACE of a specimen for images that look 3D
What is cell theory?
- all living organisms are composed of one or more cells
- cells are the smallest units of life
- new cells come only from pre-existing cells by cell division
- cell structure is correlated to cellular function
Basic features of ALL cells
- plasma membrane
- cytoplasm/cytosol
- chromosomes
- ribosomes
Characteristics of prokaryotes
- Lack nucleus
- lack various internal structures bound with phospholipid membranes
- small
- simple structures
- composed of bacteria and archaea
Eukaryotes
- true nucleus
- internal membrane-bound organelles
- larger
- more complex structures
- composed of algae, Protozoa, fungi, and animals, and plants
In the nucleotide region majority of prokaryotes have ____ circular chromosome
And eukaryotes it’s linear and has ____ copies
23 pairs
46 total
1,2
In prokaryotes the DNA is in the….
Nucleoid region
Bacteria cell walls are made of ____________
Archaea cell walls are made of ____________
Peptidoglycan
Pseudomurein
Basic features if bacterial cells
- plasma membrane
- cytoplasm/cytosol
- nucleoid
- ribosomes
Ribosomes are not organelles because they lack a __________
Membrane
Where are ribosomes made?
In the nucleolus
What is beneath the nuclear envelope?
Nuclear lamina- gives it shape
Describe the nuclear envelope
Double membrane/ 2 phospholipid bilayers on top of each other
What are lysosomes
Membranous sac of hydrolysis enzymes/ uses water to break down stuff
Lysomal enzymes are made by the er
Phagocytosis
When lysosomes break down something from outside the cell
Autophagy
When lysomes break down something within the cell
Where are vacuoles derived from?
The golgi of ER
Found in both animal and plant cells
Oxidative organelles in both plants and animals
Peroxisomes
A stack of thylakoids in chloroplast is called
Granum
Which cellular structure is common to all three domains of life?
Phospholipid bilayer cell membrane
The structures of chloroplast
Outer membrane
Inner membrane
Taylakoids, membranous sacs (a stack is called granum)
Stroma, the internal fluid
Mitochondria and chloroplast have similarities with ________
Bacteria
Envelopes by a double membrane
Contain free ribosomes and circular DNA
Grows and reproduces somewhat independently in cells
Enzymes responsible for biosynthesis of membrane lipids are located in what part of an animal cell?
Smooth ER
What is the order of exocytosis or secretion pathway?
Rough ER, transport vesicle, golgi, transport vesicle, plasma membrane
Specialized metabolic compartments binded by a SINGLE membrane
Peroxisome
Toxic molecules broken down
- general function to catalyze certain reactions that break down molecules by removing hydrogen or adding oxygen
- by product of reaction is H2O2
- catalase breaks down H2O2 into water and oxygen
Peroxisomes: oxidation
The cytoskeleton is _________ the plasma membrane
Beneath
Network of fibers extending throughout the cytoplasm
Organizes cell’s structure and activities, anchoring many organelles
Cytoskeleton
What is the cytoskeleton composed of?
Mircotubules
Mircofiliments
Intermediate filaments
Component of the cytoskeleton that is involved with cell division
Dynamic
Mircotubule
Component of the cytoskeleton Made of actin, smallest diameter
Dynamic
Microfilment
Component of the cytoskeleton, medium size, nucleus it’s shape.
Intermediate filaments
- Hollow rods about 25nm in diameter and about 200 nm to 25 microns long
- function is shaping cell, guide movement of organelles, separating chromosomes during cell division
Microtubules
What is a pair of centrosomes called?
Centrozome
In many cells, mircotubules grow out from a ___________ near the nucleus
Centrosome
- “Microtubule-organizing center”
- cell centrioles (a pair In animal cells), 9 triplets of microtubules arranged in a ring
Centrosomes
Do plants have centrosomes
No
What is cilla and flagella made of?
Microtubules
The base of cilla and flagella looks like a ___________
Basil body and Dynein
9 doubles, 2 in the middle
Centriole
- Double chain of actin subunits
- forms a 3D network just inside the plasma membrane to help support the cells shape and provide strength
- intercellular movement
- cell movement
- cytokinesis
Microfilaments (actin filaments)
Microfilments that function in cellular motility contain the protein ________ in addition to actin ________
Myosin, actin
What drives amoeboid movement?
Microfiliments by actin and myosin
A circular flow of cytoplasm within cells that occurs in plants
Movement from actin - myosin
Cytoplasmic steaming
Support cell shape and fix organelles in place
More permanent cytoskeleton fixtures than the other two classes
Beneath the envelope
Intermediate fibers
Protects the plant cell, maintains its shape, and prevents excess uptake of water.
Cellular fibers embedded in other polysaccharides and protein
Cell walls of plants
Openings in cell walls, channels that perforate plant cell walls
-water and small solutes (and sometimes proteins and RNA) can pass from cell to cell
Plasmodesmata
Layers of plant cell walls
Primary cell wall- relatively thin and flexible
Middle lamella-think layer between primary walls of adjacent cells (holds them together)
Secondary cell wall- only in some cells, added between the plasma membrane and the primary wall
Animal cells lack cell walls but are covered by an elaborate _______________
Extracellular matrix (ECM)
The ECM is made of up of …..
Glycoproteins and other macromolecule
Functions of the ECM
- support
- adhesion
- movement
- regulation
- membranes of neighboring cells are pressed together, preventing leakage of extracellular fluid
- held together along the entire space
Tight junctions
- (Anchoring junctions), fasten cell’s together into strong sheets
- held just in one spot
Desmosomes
(Communicating junctions) provide cytoplasmic channels between adjacent cells
Gap junction
