Unit 3A Flashcards
Which of the characteristics of life can a cell perform?
all of them
Describe cell theory.
There are 5 components.
All organisms are made of cells
The cell is the smallest unit of life
The structure and function of an organism is due to the activities of its cells
Cells come from pre-existing cells (all cells can trace their ancestry back to the first living cell)
Because of common ancestry, cells of all species have many chemical and metabolic similarities
Describe the size of most cells.
microscopic
Name a common cell visible to the eye.
eggs
Name the terms for the different shapes of cells.
There are 9. Squamous Cuboidal Columnar Polygonal Stellate Spheroid Discoid Fusiform Fibrous
Name an alternate name for plasma membrane.
Cell membrane.
Describe the most basic features of the plasma membrane.
The outer boundary of the cell.
Separates the cell from its outside environment.
Name and describe the regions created by the plasma membrane.
There are two. Intracellular region (inside the cell) Extracellular region (outside the cell)
Name two important functions of the plasma membrane.
Communication to and from other cells.
Regulating the entry and exit of materials from the cell.
Define cytoplasm.
The stuff inside the cell
including organelles
Describe cytosol.
The fluid part of cytoplasm.
(90% water)
(also, proteins, oxygen, and other chemicals)
Describe Organelles
structures that perform specific functions.
Most are surrounded by a membrane.
Describe the functions of the nucleus.
control center
directs all cell activities
contains DNA
Describe the form of the nucleus.
largest organelle, easily seen in a microscope
surrounded by a membrane (nuclear envelope)
nuclear envelope has nuclear pores that allow entry and exit of materials
How many nuclei do most cells have?
One.
Define multinuclear.
More than one nucleus.
Define anuclear.
Has no nucleus.
Name a cell type that has more than one nucleus.
Skeletal muscle.
Define nucleolus.
special region that makes ribosomes
Define Nucleoplasm.
watery material inside nucleus
Describe the functions of mitochondria.
makes energy for the cell
cellular respiration
carb + O2 -> CO2 + water + ATP
(catabolic, exergonic)
Describe the form of mitochondria.
A larger organelle, oval. Surrounded by two membranes. Inner membrane has folds called cristae. Region inside the folds is called matrix. The outer membrane forms a boundary.
Describe the functions of a lysosome.
Autophagy
Apoptosis
catabolizes glycogen to glucose
destroys pathogens (or other cells!)
Define autophagy
destroying unwanted intracellular materials.
Define apoptosis.
cell destroys itself
Describe the form of a lysosome.
Sack-like organelle.
Inside are digestive enzymes.
Inside is highly acidic (pH = 2 wow!)
Describe some of the autophagy performed by lysosomes.
Chemicals such as proteins, fats, drugs
Worn out organelles
viruses, bacteria, or other cells
Give some examples of apoptosis.
Cells of the uterus after giving birth.
Cells during development of embryo/fetus
Describe the functions of a peroxisome.
destroys certain substances
Give examples of substances handled by peroxisomes.
Free radicals
Hydrogen peroxide
Some fats
Where are peroxisomes abundant?
liver and kidney cells
Describe the function of ribosomes.
protein synthesis from amino acids
Describe the form of ribosomes.
a very tiny organelle (can only be seen by electron microscope)
made of RNA and proteins
does not have a membrane
Describe the locations of ribosomes
There are two.
attached to rough ER
some float freely in the cytoplasm
What does ER stand for?
Endoplasmic Reticulum
Describe the structure of endoplasmic reticulum
a channel that branches from the nucleus and weaves throughout the cytoplasm
What are the types of endoplasmic reticulum?
There are two.
Rough ER
Smooth ER
Describe the functions of rough endoplasmic reticulum.
Attached ER make proteins
newly made proteins are taken in and the ER and processes them
Give examples of ways the rough endoplasmic reticulum processes proteins.
adding a carbohydrate group
facilitating protein folding to tertiary/quaternary structure
Where do the proteins from rough endoplasmic reticulum typically end up?
There are two places.
secreted out of the cell
become part of the cell membrane
Describe the functions of smooth endoplasmic reticulum
Makes some fatty acids and hormones
In liver: degrades chemicals
In cardiac and skeletal muscle: stores and releases Ca+ cations
Where is smooth endoplasmic reticulum abundant?
There are three places.
Liver cells.
Muscle cells.
Glands in ovaries/testes.
Describe the structure of the golgi complex
channel system in the cytoplasm
Describe the functions of the golgi complex
There are four. Modifies proteins made in the rough endoplasmic reticulum Sorts and packages proteins to send out Sends packaged proteins in vesicles Forms lysosomes
Describe the structure of the cytoskeleton.
Network of protein filaments.
Extends throughout the cytoplasm.
Non-membranous.
What are the types of filament parts of the cytoskeleton.
There are three.
Microfilaments.
Intermediate filaments.
Microtubules.
Describe the form microfilaments.
made of actin proteins
the smallest filament of cytoskeleton
Describe the functions of Microfilaments.
Cellular movement such as muscle contraction
helps cytoplasm divide during cytokinesis
supports the cell membrane, shape, and microvilli
Describe the form of intermediate filaments.
middle size of the cytoskeleton filaments
very strong
Describe the function of intermediate filaments.
Reinforces areas of mechanical stress
anchors organelles in place
forms cell junctions
Describe the form of microtubules.
hollow, made of tubulin (protein)
What are the functions of microtubules?
There are four.
Cell shape.
Movement of organelles and vesicles (like a cable car)
Forms mitotic spindle to pull chromosomes during mitosis
What is the form of the centrosome?
The center point of microtubules.
A region near the nucleus.
Contains the centrioles.
What are the functions of the centrosome?
microtubules organizing center
forms microtubules
What is the form of centrioles?
a barrel-like structure of microtubules
What is the function of the centrioles?
acts as a seed to build more microtubules
Name the structure types of cellular projections.
There are two types.
Of the cell membrane.
Of the cytoskeleton.
Name the cellular projections.
There are three.
Cilia C1
Describe the form of microvilli
finger like projections
formed of cell membrane
Describe the function of microvilli
increased surface are for increased absorption
Where are microvilli found throughout the body?
There are two places.
Kidneys
Liver
Describe the form of cilia
short hair-like
made of cytoskeleton microtubules
(remember: cilia has one hair-like L)
Describe the function of cilia
sweeps extracellular material across cell
Where are microvilli found throughout the body?
There are three examples.
trachea
oviduct
inner ear
Describe the form of flagella
whip-like tail
made of cytoskeleton microtubules
Describe the function of flagella
movement of the entire cell in its environment
Where is the flagella found in the body?
It is only found in one place.
Sperm cells!