Unit 3 cell stuctures Flashcards
what is the cell theory
all living things composed of cells and all cells come from other cells
what are the earliest types of microscopes and how does it work
light microscopes
-visible light passes through a sample and glass lenses
what is the difference between objective lens and ocular lens
objective lens - magnifies up to 10x +
ocular lens - magnifies to 10x
define magnification
increase in an objects image size compared with its actual size
Notation: LM 230x
define resolution
measure of clarity of an image
how does a electron microscope work
focuses beams of electrons through a specimen sample
what are the 2 different types of electron microscopes
- Scanning electron microscope
- Transmission electron microscope
how does a scanning electron microscope
used to study the architecture of a cell
makes a 3d image
how does a transmission electron miscroscope
electron beam passed through a very thin section of specimen
what are the limitations of electron and light microscopes
electron microscopes
- cannot look at live samples
light microscopes
- cannot see small parts of the cell
what are the two types of cells
prokaryotic cells
eukaryotic cells
what are the structures that are common to all life
plasma membrane: surrounds the cell
Ribosomes: machinery for protein synthesis
Cytosol: aqueous solution in the cells
DNA: one or more chromosomes
Cytoplasm: all contents of the inside of the cells
what is the function of a plasma membrane
regulates the flow of material in and out of the cells
what can pass through a cell membrane
-small non-polar molecules
-polar compounds (through channel protein)
-large molecules (through transport proteins)
what are organelles
“little organs”
membrane bound structures that perform specific tasks
what is the function of organelles
- genetic control of cell
- Manufacture, distribution, and breakdown of molecules
- Energy processing
- Structural support, movement, and communication between cells
define cellular metabolism
chemical activities of the cell
-each organelle has its own internal chemical conditions
what organelles are only found in animal cells
lysosomes and centrosomes
flagella and cilia
what organelles are only found in plant cells
rigid cell wall
Plasmodesma
Chloroplasts
large central vacuole
what is the function of the nucleus
contain the cells genetic instructions (DNA)
controls the cells activities by directing protein synthesis
what is DNA organized into
Chromosomes
how many chromosomes does a human had
46 Chromosomes
What is chromatin
the complex of proteins and DNA
Define a Nuclear envelope
double membrane enclosing the nucleus
define nucleolus
location where ribosomal RNA (rRNA) is synthesized
Define ribosomes
parts of cell that use instructions from the nucleus to build proteins
what are the 2 different types of ribosomes
-free ribosomes
-bound ribosomes
define Free ribosomes
suspended in the cytosol
define bounded ribosomes
attached to the outside of the endoplasmic reticulum and nucleus
what is the endomembrane system
internal membranes involved in most cellular functions
What organelles are in the endomembrane system
-nuclear envelope
-endoplasmic reticulum
-Golgi apparatus
-lysosomes
-vesicles
-vacuoles
-plasma membrane
what are vesicles
sacs made of membrane
what is the Endoplasmic reticulum (ER)
network of flattened sacs and tubules
what is the function of the ER
manufacturing site in the cell
-vesicles bud from ER to travel to other organelles
what does the Smooth ER do
-synthesis lipids
-storage of calcium ions
-detoxification
what does the Rough ER do
-excrete proteins for the cell
-synthesizes new membrane fragments
what is the function of a Golgi Apparatus
warehouse and processing station for molecules produced by the ER
define a lysosome
membrane-enclosed sac of digestive enzymes
what does a lysosome do
-provides an acidic environment for its enzymes to function
- protects the cell from the acidic conditions
what are lysosomal diseases
diseases in which lysosomal enzymes are missing
what are the 2 different vacuoles
-food vacuoles
-contractile vacuoles
what does a contractile vacuole do
collect water or expels the water
define the central vacuole
absorbs water allowing cell to grow in size
what looks like it belongs in the Endomembrane system but it doesnt
Peroxisomes
what is the function of peroxisomes
break down fatty acids to use as cellular fuel
detoxification in liver
what 2 organelles are known as the energy converting organelles
- Mitochondrion
- Chloroplasts
what is the function of the Mitochondrion
carries out cellular respiration in eukaryotic cells
what is the Cristae
the inner membrane of the mitochondrion that is highly folded
what is the intermembrane space
region in between the inner and outer membranes
what is the mitochondrial matrix
contains mitochondrial DNA, ribosomes and enzymes
what is the function of Chloroplasts
Photosynthesis: converts solar energy into chemical energy
Define Stroma
think fluid inside the inner membrane
define Thylakoids
networks of interconnected membranous sacs
define Granum
Stacks of Thylakoids
Define Chlorophyll
inside in the Thylakoid membranes to trap solar energy
what is the Endosymbiont Theory
mitochondria and chloroplasts used to be small prokaryotes that began living inside larger cells
how do Mitochondria and chloroplasts resemble prokaryotic cells
single circular DNA molecule
Ribosomes similar to prokaryotic ones
reproduce similarly like prokaryotes
define the Cytoskeleton
networks of protein fibers extending throughout the cells
what are the 3 different types of Cytoskeleton fibers
- Microtubules
- Microfilaments
- Intermediate filamentsd
Define microtubules
-straight hollow tubes composed of globular proteins
-found in centrosome
what is the function of Microtubules
- support and shape cell
- guides the movement of chromosomes
-main component in flagella and cilia
define intermediate filaments
fibor filaments supercoiled into cables
in animal cells
what is the function of intermediate filaments
reinforce cell shape and anchor some organelles
define microfilaments (actin filaments)
rods of globular actin proteins
what is the function of microfilaments
- inside cell membrane to support cell shape
- involved in cell movement
define Cilia
- short hairlike strands coming from cell
- moving in a sweeping motion
Define Flagella
-long tail like appendage on cells
- found on animal sperm cells
what is the Extracellular matric
- holds cells together in tissues
- protects and supports the plasma membrane
define tight functions
plasma membranes of adjacent cells are knit tightly
define anchoring junctions
intermediate filaments fasten cells together into long sheets
define Gap junctions
channels or pores that allow the flow of small molecules from one cell to another
