Chapter 3: Cell Structures and Their Functions Flashcards
Specialized structures
Organelles
Organelle containing the cell’s genetic material
Nucleus
Living material that surrounding the nucleus
Cytoplasm
Cytoplam is enclosed by
Cell membrane or plasma membrane
Basic living unit of all organisms
Cell
Contains genetic material of cell (DNA) and nucleoli
Nucleus
Site of RNA synthesis and ribosomal subunit assembly
Nucleus
Site of protein synthesis
Ribosomes
Has many ribosomes attached; site of protein synthesis
Rough endoplasmic reticulum
Site of lipid synthesis; participates in detoxification
Smooth endoplasmic reticulum
Modifies protein structure and packages proteins secretory vesicles
Golgi apparatus
Contains materials produced in the cell; formed by the Golgi apparatus;secreted by exocytosis
Secretory vesicle
Contains enzyme that digest material taken into the cell
Lysosome
Site of aerobic respiration and major site of ATP synthesis
Mitochondrion
Supports cytoplasm; assists in cell division and forms components of cilia and flagella
Microtubule
Facilitate the movement of chromosomes during cell division
Centrioles
Move substances over surfaces of certain cells
Cilia
Propel sperm cells
Flagella
Increase surface area of certain cells
Microvilli
Functions of the cell
Cell metabolism and energy use
Synthesis of molecules
Communication
Reproduction and inheritance
Chemical reactions that occur within cells are collectively called
Metabolism
Outermost component of a cell
Cell membrane
Encloses the cytoplasm and forms the boundary between material inside the cell and material outside it
Cell membrane
Substances outside the cell
Extracellular
Substances inside the cell
Intercellular
Acts as a selective barrier that determines what moves into and out of the cell
Cell membrane
Major molecules that make up the cell membrane
Phospholipids and proteins
Model of structure of the cell membrane
Fluid mosaic model
Form a double layer of molecules
Phospholipid
Hydrophilic (water loving) and therefore face the extracellular and intracellular fluids of the cell
Polar, phosphate containing ends of phospholipids
Hydrophobic (water fearing) and therefore face away from the fluid on either side of the membrane
Nonpolar, fatty acid ends of phospholipids
Forms a lipid barrier between the inside and outside of the cell
Double layer of phospholipids
Involved with the movement of substances through the cell membrane
Membrane channels and carrier molecules
Part of an intercellular communication system that enables cell recognition and coordination of the activities of cells
Receptor molecules
Allow some substances, but not others, to pass into or out of the cells
Selectively permeable
Does not require the cell to expend energy
Passive membrane transport
Does require the cells to expend energy, usually in the form of atp
Active membrane transport
Diffusion, osmosis, and facilitated diffusion
Passive membrane transport mechanism
Include active transport, secondary active transport, endocytosis, and exocytosis
Active membrane transport mechanism
Composed of one or more substances
Solution
Substances
Solutes
Predominant Iiquid or gas
Solvent
Move from an area of higher concentration of a solute to an area of lower concentration of that same solute In solution
Diffusion
Difference in the concentration of a solute in a solvent between two points
Concentration gradient
Major molecules that make up the cell membrane
Phospholipids and proteins
Model of structure of the cell membrane
Fluid mosaic model
Form a double layer of molecules
Phospholipid
Hydrophilic (water loving) and therefore face the extracellular and intracellular fluids of the cell
Polar, phosphate containing ends of phospholipids
Hydrophobic (water fearing) and therefore face away from the fluid on either side of the membrane
Nonpolar, fatty acid ends of phospholipids
Forms a lipid barrier between the inside and outside of the cell
Double layer of phospholipids
Involved with the movement of substances through the cell membrane
Membrane channels and carrier molecules
Part of an intercellular communication system that enables cell recognition and coordination of the activities of cells
Receptor molecules
Allow some substances, but not others, to pass into or out of the cells
Selectively permeable
Does not require the cell to expend energy
Passive membrane transport
Does require the cells to expend energy, usually in the form of atp
Active membrane transport
Diffusion, osmosis, and facilitated diffusion
Passive membrane transport mechanism
Include active transport, secondary active transport, endocytosis, and exocytosis
Active membrane transport mechanism
Composed of one or more substances
Solution
Substances
Solutes
Predominant Iiquid or gas
Solvent
Move from an area of higher concentration of a solute to an area of lower concentration of that same solute In solution
Diffusion
Difference in the concentration of a solute in a solvent between two points
Concentration gradient
Contains genetic material of cell (DNA) and nucleoli
Nucleus
Site of RNA synthesis and ribosomal subunit assembly
Nucleus
Site of protein synthesis
Ribosomes
Has many ribosomes attached; site of protein synthesis
Rough endoplasmic reticulum
Site of lipid synthesis; participates in detoxification
Smooth endoplasmic reticulum
Modifies protein structure and packages proteins secretory vesicles
Golgi apparatus
Contains materials produced in the cell; formed by the Golgi apparatus;secreted by exocytosis
Secretory vesicle
Contains enzyme that digest material taken into the cell
Lysosome
Site of aerobic respiration and major site of ATP synthesis
Mitochondrion
Supports cytoplasm; assists in cell division and forms components of cilia and flagella
Microtubule
Facilitate the movement of chromosomes during cell division
Centrioles
Move substances over surfaces of certain cells
Cilia
Propel sperm cells
Flagella
Increase surface area of certain cells
Microvilli
Functions of the cell
Cell metabolism and energy use
Synthesis of molecules
Communication
Reproduction and inheritance
Chemical reactions that occur within cells are collectively called
Metabolism
Outermost component of a cell
Cell membrane
Encloses the cytoplasm and forms the boundary between material inside the cell and material outside it
Cell membrane
Substances outside the cell
Extracellular
Substances inside the cell
Intercellular
Acts as a selective barrier that determines what moves into and out of the cell
Cell membrane
Major molecules that make up the cell membrane
Phospholipids and proteins
Model of structure of the cell membrane
Fluid mosaic model
Form a double layer of molecules
Phospholipid
Hydrophilic (water loving) and therefore face the extracellular and intracellular fluids of the cell
Polar, phosphate containing ends of phospholipids
Hydrophobic (water fearing) and therefore face away from the fluid on either side of the membrane
Nonpolar, fatty acid ends of phospholipids
Forms a lipid barrier between the inside and outside of the cell
Double layer of phospholipids
Involved with the movement of substances through the cell membrane
Membrane channels and carrier molecules
Part of an intercellular communication system that enables cell recognition and coordination of the activities of cells
Receptor molecules
Allow some substances, but not others, to pass into or out of the cells
Selectively permeable
Does not require the cell to expend energy
Passive membrane transport
Does require the cells to expend energy, usually in the form of atp
Active membrane transport
Diffusion, osmosis, and facilitated diffusion
Passive membrane transport mechanism
Include active transport, secondary active transport, endocytosis, and exocytosis
Active membrane transport mechanism
Composed of one or more substances
Solution
Substances
Solutes
Predominant Iiquid or gas
Solvent
Move from an area of higher concentration of a solute to an area of lower concentration of that same solute In solution
Diffusion
Difference in the concentration of a solute in a solvent between two points
Concentration gradient
location of ribosomes
in cytoplasm
location of rough endoplasmic reticulum
in cytoplasm
location of smooth endoplasmic reticulum
in cytoplasm
location of golgi apparatus
in cytoplasm
location of secretory vesicle
in cytoplasm
location of lysosome
in cytoplasm
location of mitochondrion
in cytoplasm
location of microtubule
in cytoplasm
location of cilia
on cell surface with many on each cell
location of flagella
on sperm cell with one per cell
location of microvili
extensions of cell surface with many on each cell
constantly allow ions to pass through
leak channels
limit movement of ions across the membrane by opening and closing
gated channels
diffusion of water (a solvent) across a selectively permeable membrane, such as the cell membrane, from a region of higher water concentration to one of lower water concentration
osmosis
force required to prevent the movement of water across a selectively permeable membrane
osmotic pressure
measure of the tendency of a water to move by osmosis across a selectively permeable membrane
osmotic pressure
moves water out of the tube back into the distilled water
hydrostatic pressure
solution usually has a lower concentration of solutes and a higher concentration of water relative to the cytoplasm of the cell
hypotonic
water moves by osmosis into the cell, causing it to swell
lysis
concentrations of various solutes and water are the same on both sides of the cell membrane
hypertonic
solution usually has higher concentration of solutes and a lower concentration of water relative to the cytoplasm of the cell
hypertonic
cell shrinkage
crenation
proteins within the cell membrane are involved in carrier- mediated transport mechanism, which move large, water-soluble molecules or electrically charged ions across the cell membrance
carrier molecules
only specific molecules are transported by the carriers
specificity
Three kinds of carrier mediated transport
facilitated diffusion, active transport, and secondary active transport
carrier mediated transport process that moves substances across the cell membrane from an area of higher concentration to lower conentration
facilitated diffusion
carrier mediated process that moves substances across the cell membrane from reqions of lower concentration to those of higher concentration against a concentration gradient
active transport
moves Na+ out of cells and K= into cells
sodium potassium pump
active transport of one substance, such as Na+ across the cell membrane, establishing a concentration gradient
secondary active transport
diffusing substance moves in the same direction as the transported substance
cotransport
membrane bound sacs
vesicles
uptake of material through the cell membrane by the formation of a vesicle
endocytosis
specific substance binds to the receptor molecule, endocytosis is triggered, and the substance is transported into the cells
receptor-mediated endocytosis
used for endocytosis when solid particles are ingested
phagocytosis
distinguished from phagocytosis in that much smaller vesicle are formed, and they contain liquid rather than particles
pinocytosis
accumulate materials for release from the cell
secretory vesicles
material in the vesicle is eliminated from the cell
exocytosis
large organelle located near the center of the cell
nucleus
consists of outer and inner membranes with a narrow space between them
nuclear envelope
materials can pass in or out of the nucleus
nuclear pores
nuclei of human cells contain 23 pairs of
chromosomes
the chromosome that are largely coiled and collectively called
chromatin
little nucleus
nucleoli
different fuse bodies with no surrounding membrane that are found within the nucleus
nucleoli
produced within the nucleolus, to form large and small ribosomal subunits
ribosomal ribonucleic acid (rRNA)
organelles where proteins are produced
ribosomes
ribosomes that are not attached to any other organelle
free ribosomes
series of membranes forming sacs and tubules that extends from the outer nuclear membrane into the cytoplasm
endoplasmic reticulum
ER with ribosomes attatched to it
Rough ER
ER without ribosomes
Smooth ER
site for lipid synthesis and participates in detoxification of chemicals within cells
Endoplasmic reticulum
stores calcium cells (skeletal muscle cells)
Smooth ER
consists of closely packed stacks of curved, membrane-bound sacs
Golgi Apparatus
collects modifies, packages and distributes proteins and lipids manufactured by the ER
Golgi Apparatus
small, membrane-bound sac that transports or stores materials within cells
vesicle
membrane-bound vesicles formed from the Golgi Apparatus
lysosomes
contain a variety of enzymes that function as intracellular digestive systems
Lysosomes
small, membrane-bound vesicles containing enzymes that break down fatty acids, amino acids, and hydrogen peroxide
peroxisomes
small organelles with inner and outer membranes separated by a space
mitochondria
folds in the mitochondria
cristae
major site of adenosine triphosphate production within cells
mitochondria
consists of proteins that support the cell, hold organelles in place and enable the cell to change shape
cytoskeleton
hollow structures formed from protein subunits
microtubules
perforrm variety of roles, such as helping support the cytoplasm of cells, assisting in cell division, and forming essential component of certain organelles such as cilia and flagella
microtubules
small fibrils formed from protein subunits that structurally support the cytoplasm
microfilaments
fibrils formed from protein subunits that are smaller in diameter than microtubules but larger in diameter than microfilamets
intermediate filaments
specialized zone of cytoplasm close to the nucleus, where microtubule formation occurs
centrosome
small, cylindrical, organelle composed of nine triplets
centrioles
composed of microtubules, organized in a pattern similar to that of centrioles
cilia
structure similar to that of cilia but are much longer
flagella
propels the sperm cell
flagella
specialized extensions of the cell membrane that are supported by microfilaments but they do not actively move as cilia and flagella do
microvili
increase the surface area of those cells
microvili
DNA contains the information that directs protein synthesis
gene expression
consists of nucleotides joined together to form two nucleotides strands
DNA molecule
function as chemical letters that form chemical “words”
nucleotides
sequence of nucleotides that provides a chemical set of instructions for making a specific protein
gene
gene expression involves two steps
transcription
translation
making a copy of the gene necessary to make a particular protein
transcription
changing of something from one form to another
translation
copy of gene necessary to make a particular protein
messenger RNA (mRNA)
travels from the nucleus to the ribososmes in the cytoplasm, where information in the copy is used to construct a protein by means of translation
messenger RNA (mRNA)
carry amino acids to the ribosomes
transfer RNAs (tRNAs)
each nucleotide of DNA contains one
Adenine
Cytosine
Guanine
each nucleotide of mRNA contains
uracil
adenine
cytosine
guanine
synthesis of proteins based on the information in mRNA, occurs at the ribosomes
translation
series of three nucleotides of tRNA, pairs with the codon of mRNA
anticodon
enzyme associated with the ribosomes causes the formation of
peptide bond
cell cycle includes two major phases
nondividing phase, called interphase
dividing phase
at the end of ___________, a cell has two complete sets of genetic material
interphase
formation of daughter cells from a single parent cell
Cell division
chromosomes if the person is female
2 X chromosomes
chromosomes if the person is male
an X chromosome and a Y chromosome
remaining 22 chromosomes
autosomes
cells of the body, except those that give rise to sex cells divide by
mitosis
parent cell divides to form two daughter cells with the same amount and type of DNA as the parent cell
mitosis
four stages off mitosis
prophase
metaphase
anaphase
telophase
chromatin condenses to form visible chromosomes
prophase
identical strands of chromatin
chromatids
specialized region at the center part
centromere
microtubules call spindle fibers extend from the centrioles to the centromeres
prophase
centrioles divide and migrate to each pole of the cell
prophase
nucleolus and nuclear envelope disapppear
late prophase
chromosomes align near the center of the cell
metaphase
at he beginning the chromatids separate. When this happens each chromatid is then called a chromosome
anaphase
at this point two identical sets of 46 chromosomes are present in the cell
anaphase
each of the two sets of 46 chromosomes is moved by the spindle fibers toward the centriole at one of the poles of the cell
anaphase
at the end of _______ , each set of chromosomes has reached an opposite pole of the cell , and the cytoplasm begins to divide
anaphase
chromosomes in each of the daughter cells become organized to form two separate nuclei
telophase
chromosomes begin to unravel and resemble the genetic material dutring the interphase
telophase
process by which cells develop with specialized structures and functions
differentiation
the time between cell divisions
interphase
DNA is found as thin threads of chromatin in the nucleus
interphase
DNA replication occurs during
interphase
Chromatin condenses into chromosomes. Each chromosome consists of two chromatids joined at the centromere. The centrioles move to the opposite ends of the cell, and the nucleolus and the nuclear envelope disappear
prophase
the cchromosomes align in the center of the cell in association with the spindle fibers
metaphase
chromatids separate to form two sets of identical chromosomes. The chromosomes, assisted by the spindle fibers, move toward the centrioles at each end of the cells
anaphase
chromosomes, disperse, the nuclear envelopes and nucleoli form, and the cytoplasm continues to divide to form two cells
telophase
programmed cell death, is a normal process by which cell numbers within various tissues are adjusted and controlled
apoptosis
