The Cell: Parts and its Function Flashcards
In 1665, __________ used a microscope to examine a tTHIN SLICE OF CORK (dead plant cells)
Robert Hooke
What he saw looked like small boxes. He is responsible for naming cells. He called them “CELLS” because they looked like the small rooms that monks lived in called Cells
Robert Hooke
In 1673, __________ (a Dutch microscope maker), was first to view organism (LIVING THINGS).HE used a simple, handheld microscope to view POND WATER & SCRAPINGS FROM HIS TEETH
Leeuwenhoek
In 1838, a German botanist named _______ concluded that all PLANTS WERE MADE OF CELLS . HE is a cofounder of the cell theory
Matthias Schleiden
In 1839, a German zoologist named ________ concluded that all ANIMLAS WERE MADE OF CELLS. HE also cofounded the cell theory
Theodore Schwann
In 1855, a German medical doctor named __________ observed, under the microscope, CELLS DIVIDING. He reasoned that all cells COME FROM OTHER PRE-EXISITING CELLS by cell division
Rudolph Virchow
CELL THEORY
All living things are made of cells
Cells are the basic unit of structure and function in an organism (basic unit of life)
Cells come from the reproduction of existing cells (cell division)
blob-like structure
amoeba
Cells differ in _____, some are microscopic and only few are not.
sizes
two type of cells
prokaryotic and eukaryotic cells.
All cells share four common components:
a plasma membrane, cytoplasm, DNA, ribosomes.
an outer covering that separates the cell’s interior from its surrounding environment
plasma membrane
consisting of a jelly-like region within the cell in which other cellular components are found
cytoplasm
The genetic material of the cell
DNA
Unlike Archaea and eukaryotes, bacteria have a cell wall made of ________, comprised of sugars and amino acids, and many have a polysaccharide capsule
peptidoglycan
acts as an extra layer of protection, helps the cell maintain its shape, and prevents dehydration
cell wall
used for locomotion
Flagella
used to exchange genetic material during a type of reproduction called conjugation.
pili
a cell that has a membrane-bound nucleus and other membrane-bound compartments or sacs, called organelles, which have specialized functions.
eukaryotic cell
The word eukaryotic means “_______” or “_________”
true kernel OR true nucleus
The word “organelle” means “____________”
little organ
have specialized cellular functions
organelles
They have NO TRUE NUCLEUS as the DNA is not contained within a membrane or separated from the rest of the cell, but is coiled up in a region of the cytoplasm called the nucleoid.
Prokaryotic Cells
most common bacteria shapes
spherical, rod-shaped, and spiral.
Found in some bacterial cells, this ADDITIONAL OUTER COVERING protects the cell when it is engulfed by other organisms, assists in retaining moisture, and helps the cell adhere to surfaces and nutrients.
Capsule
an OUTER COVERING that PROTECTS the bacterial cell and GIVES IT SHAPE
Cell Wall
a GEL-LIKE substance composed mainly of water that also contains enzymes, salts, cell components, and various organic molecules.
Cytoplasm
surrounds the cell’s cytoplasm and REGULATES THE FLOW OF SUBSTANCES in and out of the cell.
Cell Membrane or Plasma Membrane
HAIR-LIKE STRUCTURES on the surface of the cell that attach to other bacterial cells.
Pili (Pilus singular)
Shorter pili called ______ help bacteria attach to surfaces.
fimbriae
are long, WHIP-LIKE protrusions that aid in cellular LOCOMOTION.
Flagella
are cell structures responsible for PROTEIN PRODUCTION.
Ribosomes
are GENE-CARRYING, circular DNA structures that are NOT INVOLVED in reproduction.
Plasmids
Area of the cytoplasm that contains the single bacterial DNA molecule.
Nucleoid Region
Prokaryotic cells lack organelles found in eukaryoitic cells such as ________________________________________.
mitochondria, endoplasmic reticuli, and Golgi complexes
According to the ________________, eukaryotic organelles are thought to have evolved from prokaryotic cells living in endosymbiotic relationships with one another.
Endosymbiotic Theory
two important components of the cell
plasma membrane and the cytoplasm.
made up of a PHOSPHOLIPID BILAYER with embedded proteins that separates the internal contents of the cell from its surrounding environment.
Plasma Membrane
a lipid molecule composed of two fatty acid chains, a glycerol backbone, and a phosphate group.
phospholipid
regulates the passage of some substances, such as organic molecules, ions, and water, preventing the passage of some to maintain internal conditions, while actively bringing in or removing others
plasma membrane
The plasma membranes of cells that specialize in absorption are folded into fingerlike projections called _________
microvilli
comprises the contents of a cell between the plasma membrane and the nuclear envelope (a structure to be discussed shortly). It is made up of organelles suspended in the gel-like cytosol, the cytoskeleton, and various chemicals.
Cytoplasm
Even though the cytoplasm consists of 70 to 80 percent water, it has a _______________, which comes from the proteins within it
semi-solid consistency
a NETWORK OF PROTEIN FIBERS that helps to maintain the shape of the cell, secures certain organelles in specific positions, allows cytoplasm and vesicles to move within the cell, and enables unicellular organisms to move independently
Cytoskeleton
three types of fibers within the cytoskeleton
microfilaments, intermediate filaments, and microtubules
are the THINNEST of the cytoskeletal fibers and function in moving cellular components. They also MAINTAIN THE STRUCTURE OF MICROVILLI, the extensive folding of the plasma membrane found in cells dedicated to absorption. These components are also common in muscle cells and are responsible for muscle cell contraction.
Microfilaments
are of intermediate diameter and have structural functions, such as maintaining the shape of the cell and anchoring organelles.
Intermediate filaments
are long, hair-like structures that extend from the plasma membrane and are used to move an entire cell
Flagella
a group of membranes and organelles in eukaryotic cells that work together to modify, package, and transport lipids and proteins.
Endomembrane System
is the MOST PROMINENT ORGANELLE in a cell. It houses the cell’s DNA in the form of chromatin and directs the synthesis of ribosomes and proteins.
Nucleus
a double-membrane structure that constitutes the outermost portion of the nucleus. is punctuated with pores that control the passage of ions, molecules, and RNA between the nucleoplasm and the cytoplasm.
nuclear envelope
a SIRIES OF INTERCONNECTED MEMBRANOUS TUBULES that collectively modify proteins and synthesize lipids. However, these two functions are performed in separate areas of the endoplasmic reticulum: the rough endoplasmic reticulum and the smooth endoplasmic reticulum, respectively.
Endoplasmic Reticulum
is so named because the ribosomes attached to its cytoplasmic surface give it a STUDDED appearance when viewed through an electron microscope.
also makes phospholipids for cell membranes.
rough endoplasmic reticulum (RER)
is continuous with the RER but has few or no ribosomes on its cytoplasmic surface. The ______ functions include synthesis of carbohydrates, lipids (including phospholipids), and steroid hormones; detoxification of medications and poisons; alcohol metabolism; and storage of calcium ions.
smooth endoplasmic reticulum (SER)
he sorting, tagging, packaging, and distribution of lipids and proteins take place in the __________________, a SERIES OF FLATTENED MEMBRANOUS SACS
Golgi Apparatus/GOLGI BODY
In animal cells, the ________ are the cell’s “garbage disposal.” DIGESTIVE enzymes within the lysosomes aid the breakdown of proteins, polysaccharides, lipids, nucleic acids, and even worn-out organelles.
Lysosomes
are membrane-bound sacs that function in storage and transport.
Vesicles and vacuoles
are somewhat larger than vesicles, and the membrane of a vacuole does not fuse with the membranes of other cellular components.
Vacuoles
Can fuse with other membranes within the cell system.
Vesicles
are the cellular structures responsible for PROTEIN SYNTHESIS.
Ribosomes
are often called the “powerhouses” or “energy factories” of a cell because they are responsible for making adenosine triphosphate (ATP), the cell’s main ENERGY-CARRYING molecule.
Mitochondria
The formation of ATP from the breakdown of glucose is known as ________
cellular respiration
is a rigid covering that PROTECTS the cell, provides STRUCTURAL SUPPORT, and GIVES SHAPE to the cell.
Cell Wall
Function in photosynthesis and can be found in eukaryotic cells such as plants and algae
Chloroplasts
Able to make their own food
autotrophs
must rely on other organisms for their organic compounds or food source.
heterotrophs
Separates cell from external environment; controls passage of organic molecules, ions, water, oxygen, and wastes into and out of the cell
Plasma membrane
Provides structure to cell; site of many metabolic reactions; medium in which organelles are found
Cytoplasm
Location of DNA
Nucleoid
Cell organelle that houses DNA and directs synthesis of ribosomes and proteins
Nucleus
Protein synthesis
Ribosomes
ATP production/cellular respiration
Mitochondria
Oxidizes and breaks down fatty acids and amino acids, and detoxifies poisons
Peroxisomes
Storage and transport; digestive function in plant cells
Vesicles and vacuoles
Unspecified role in cell division in animal cells; organizing center of microtubules in animal cells
Centrosome
Digestion of macromolecules; recycling of worn-out organelles
Lysosomes
Protection, structural support and maintenance of cell shape
Cell wall
Photosynthesis
Chloroplasts
Modifies proteins and synthesizes lipids
Endoplasmic reticulum
Modifies, sorts, tags, packages, and distributes lipids and proteins
Golgi apparatus
Maintains cell’s shape, secures organelles in specific positions, allows cytoplasm and vesicles to move within the cell, and enables unicellular organisms to move independently
Cytoskeleton
Cellular locomotion
Flagella
Cellular locomotion, movement of particles along extracellular surface of plasma membrane, and filtration
Cilia
