Chapter 3&4 - Anatomy & Physiology of the Cell Flashcards
what is the earliest form of cells?
prokaryotes
What is special about eukaryotic cells?
they make up all multicellular organisms, they have a defined nucleus which holds DNA
Are larger or smaller cells more efficient?
smaller cells; they have fewer nutrient requirements
What does having multiple nuclei allow?
more activity within the cell
ex: cardiac muscle cells have two or more nuclei
What are the three essential structures of mammalian cells?
cell membrane, cytoplasm, nucleus
What is another name for the cell membrane?
plasmalemma
What is the cell membrane?
the flexible barrier that separates the cytoplasm from external environments.
what is the cell membrane made up of?
two rows of phospholipid bilayers
What do the phospholipid bilayers allow?
passive movement of lipid-soluble molecules across the membrane
ex: oxygen or CO2
what do the integral proteins do?
act as pores to allow free water movement;
contain peripheral proteins
what do peripheral proteins do?
act as enzymes; change the cell’s shape
where do internal peripheral proteins attach?
to the cytoskeleton inside the cell
where do external peripheral proteins attach?
to glycoproteins and glycolipids
What is on the surface of the cell membrane?
molecules that form glycocalyx (glycolipids and glycoproteins)
cell adhesion molecules
membrane receptors
what does contact signaling do?
it allows cells to recognize each other
what does chemical signaling do?
it allows for functions to be turned on and off
What do caveolae do?
they are pockets in the membrane that act as sensors
what do flagella do?
flagella are a long whip-like structures used to move the cell around
What do cilia do?
cilia are short spikes used to increase surface area as well as push things along the surface of the cell
what is the cytoplasm?
a gel-like substance inside the cell membrane that contains the organelles
what is the cytoplasm made up of?
cytosol, cytoskeleton, organelles
what is cytosol
the fluid of the cytoplasm
what is the cytoskeleton?
3D frame and support structure; responsible for cell division and muscle function
What are the organelles?
tiny little organs within the cell
what is the mitochondria
the organelle that makes ATP and is where respiration takes place. It contains their own DNA/RNA
what are the ribosomes?
tiny organelles that synthesize proteins, which contain a special type of RNA
Who makes proteins for the plasmalemma?
Rough ER
who makes proteins for intracellular use?
the cytoskeleton
How do organelles make their own proteins?
they copy the protein structure from DNA
What does the Rough ER do?
modify proteins from ribosomes
Where do modified proteins move after the rough ER?
into vesicles for the Golgi Apparatus
What does rough ER contain?
ribosomes
What does smooth ER do?
synthesis and storage of lipids
What does the golgi apparatus do?
receives packages from ER and modifies proteins into glycoproteins
What does the golgi apparatus do with glycoproteins?
ships them across the cell
what do lysosomes do?
contain enzymes for breaking down damaged molecules throughout the cytoplasm
What is the nucleus?
the part of the cell that contains heredity information and controls cellular processes
what are the four parts of the nucleus?
nuclear envelope, nucleoplasm, chromatin, nucleoli
What molecule makes up 60% of an animal’s body?
water
what is metabolic water
water made within the body via cellular processes
what are the two types of water loses
insensible and sensible water loss
what is insensible water loss?
water loss that cannot be easily measured
ex: breathing, passively from skin
what is sensible water loss?
water loss able to be measured
ex: urine, feces, vomiting, diarrhea, sweating
What type of fluid makes up 2/3 of the body’s fluids?
intracellular fluids
how are intracellular fluid maintained?
by cell membranes
What type of fluid makes up 1/3 of the body’s fluids?
extracellular fluids
where is intravascular fluid found?
within blood &lymph vessels (plasma)
where is interstitial fluid found?
outside of cells within the tissues; surrounding the cell
(T/F) Fluid can be shifted between intracellular and extracellular compartments
True
what is the most abundant solute found in the body?
electrolytes
what are cations
positively charged ions
what are anions?
negatively charged ions
what are the main extracellular ions?
sodium and chloride
what are the main intracellular ions?
potassium and hydrogen
What do acids release?
H+ ; known as proton donators
what do bases release?
OH- ; known as proton receivers
what occurs when acids and bases dissociate?
they become electrolytes
What happens when there is more H+ in a solution?
the greater the acidity and lower the pH in the solution
what happens when theres more OH- in a solution?
the greater the alkalinity and the higher the pH
What is the pH of water
7
what is the pH of blood
7.4
what happens when an animal gets sick?
there is a change in the electrolyte concentrations, altering the pH levels dangerously
what is osmolality
the measure of solute concentration in a fluid
what is the osmolality level of serum?
278-300 mOsmol / kg
what hormone controls serum osmolality in mammals?
antidiurectic hormone (ADH)
what has the same osmolality as normal blood?
isotonic fluids
what has a lower osmolality than normal blood?
hypotonic fluids
what has a higher osmolality than normal blood?
hypertonic fluids
in which fluid do cells function optimally?
isotonic extracellular fluids
what can occur if the extracellular fluid changes osmolality?
the cell can change shape or even rupture
what can force the movement of body fluids from one compartment to another?
hydration status of a patient
What are types of fluid products?
crystalloids and colloids
what are crystalloids for?
used for rehydrating extravascular spaces
what are isotonic crystalloids?
lactated ringers, 0.9% NaCl (normal saline)
what are hypotonic crystalloids?
0.45% NaCl (hypotonic saline)
What are colloids used for?
rehydrating intravascular spaces by pulling water from extravascular spaces
What are hypertonic solutions of colloids?
hetastarch, mannitol
what are the three phases of fluid therapy?
resuscitation, replacement, maintenance
what is the goal with resuscitation
to increase intravascular fluid volume
what fluids are used in resuscitation
crystalloids and colloids together
what occurs during resuscitation
raises blood pressure, allows for better oxygen delivery
when do we use resuscitation fluid therapy
with patients who have lost more than 30% of their intravascular fluid; blood loss & severe hydration
what is the goal of replacement fluid therapy?
to correct dehydration
how do we configure replacement values?
replacement = dehydration + ongoing losses + maintenance
what is the formula for replacement fluid therapy?
body weight (kg) x dehydration% = fluid deficit (liters)
how do you get from lbs to kg
divide lbs body weight by 2.2
when do we use maintenance fluid therapy?
on patients that are not taking in water on their own; not dehydrated, no ongoing fluid loss
Why is the cell membrane considered selectively permeable?
it is freely permeable to small molecules like water but impermeable to large molecules like hormones, nutrients, etc.
what does cell membrane permeability allow for?
the maintenance of homeostasis within the cell
what is active transport?
any transport across the membrane that requires ATP
what is passive transport?
any movement across the cell membrane that does not require ATP or energy
What is diffusion?
diffusion that takes advantage of a concentration gradient for molecules to move around
What does the movement look like with diffusion?
molecules move from an area of higher concentration to an area of lower concentration
what is the ability of a molecule to diffuse based on?
small molecular size, lipid solubility, and molecular charge
what is facilitated diffusion?
diffusion that requires the help of a carrier protein to carry larger or lipid insoluble molecules across the membrane
what are carrier proteins?
a type of integral protein within the membrane
what is osmosis?
the movement of water across the membrane against it’s gradient
what direction does water move?
opposite of diffusion
What does water’s movement in the body do?
establish a concentration equilibrium where the solute concentration is equal on both sides
What does the force of osmosis create?
osmotic pressure
what is osmotic pressure if occurring inside a body?
oncotic pressure
what is edema?
water moving into interstitial spaces excessively
what is effusion?
water moving into body cavities excessively
what is filtration?
pushing liquids through a membrane based on a pressure gradient
what is hydrostatic pressure?
the force pushing a liquid through a membrane
what is hydrostatic pressure when occurring in a body?
blood pressure
what is blood pressure based on?
strength of the pump of the heart and diameter of vessels
why does active transport require energy?
because larger molecules are being moved w/o or against a concentration gradient
what are symporters?
ions flow in same direction
what are antiporters?
ions flow in opposite direction
what is cytosis?
a vesicle forming from the membrane itself and engulfing a large particle or cell which then enters the cell
what is endocytosis?
the taking into of a cell
what is phagocytosis?
a vesicle that engulfs a solid particle
phagosome
what is pinocytosis?
a vesicle that engulfs a liquid particle
pinosome
what is receptor mediated endocytosis?
special integral proteins on the surface of the membrane which initiate phagocytosis
what is exocytosis?
excretion and secretions from cells
what is an excretion?
exocytosis of waste products
what is secretion?
exocytosis of functional manufactured molecules
mucus, neurotransmitters, histamine
what is resting membrane potential?
the distribution of charges on either side of the cell membrane
what is an uneven distribution of ions across the membrane maintained by?
a sodium-potassium pump
how do cells replicate?
in 2 phases; interphase and mitotic phase
what occurs during interphase?
cell is growing, maturing, and differentiating
what occurs during the mitotic phase?
cell is actively dividing
How do somatic cells divide and multiply?
through mitosis
how do reproductive cells multiply and divide?
through meiosis
what are the three subphases in interphase?
Growth 1 (G1), Synthetic (S), Growth Two (G2)
What occurs in G1
intense growth and activity, cell doubles in size, organelles double, centrioles replicate
What occurs in Synthetic?
DNA replication
What occurs in G2?
synthesis of enzymes and proteins needed, growth continues, centrioles ready
How is DNA replication carried out?
by proteins called replisomes; protein machines that have helpful enzymes
What does the helicase do?
unravel double helix
what does primase do?
start RNA primer
what does replicase do?
completes RNA primer
what does polymerase do?
makes the DNA strand
what does ligase do?
attaches smaller segments of DNA together on the lagging strand
what is the first step in DNA replication?
chromosomes uncoil
what is the second step in DNA replication?
histones and DNA separate
what is the third step in DNA replication?
helicase enzyme untwists the DNA and separates it into two strands
what is the fourth step in DNA replication?
free floating nucleotides form an RNA primer on the unraveled DNA strand (primase and replicase)
what is the fifth step in DNA replication?
After the primer, free floating nucleotides form the new DNA strand (DNA polymerase)
what is the sixth step in DNA replication?
RNA primer is replaced by DNA (DNA polymerase)
what is the first seventh in DNA replication?
DNA Ligase attaches small segments of DNA together
what is the eighth step in DNA replication?
original and new DNA strand form identical chromatids
what is the ninth step in DNA replication?
chromatids attach to centromeres
what are the four stages of mitotic phase?
prophase, metaphase, anaphase, telophase
what occurs during prophase?
nuclear envelope disappears, cytoskeleton microtubules disassemble, chromatin strands form ‘X’
what occurs during metaphase?
chromosomes line up centrally along the metaphase plate, centromere of chromosomes attach to spindle fibers
what occurs during anaphase?
centromeres split in half and single strand becomes its own strand, spindle fibers shorten pulling chromosomes to opposite sides, waist forms
what occurs during telophase?
chromosomes movement stops, cell separates into two, nuclear envelope emerges around unraveled chromatin threads, nucleoli forms
How does cell division end?
with cytokinesis, the separation of the two cytoplasm’s
what signals control the rate of cell division?
contact inhibition, presence of growth-inhibiting substance, production of proteins during interphase
what is contact inhibition?
when cells touch each other, they stop replicating
what are cyclins?
proteins that increase in number during certain phases of the cell
what is a cyclin dependent kinase?
always present, waiting to bind to cyclin to initiate cell division
What results in cell differentiation?
the turning off temporarily or permanently of certain genes within cells depending on their function for the body
what are genetic mutations?
errors spontaneously occurring in the order of nucleotides within a strand of DNA
what severe genetic mutations lead to?
they can have little effect or so much effect they kill the cell
What is transfer RNA (tRNA)
free floating nucleotides which attach to corresponding sections of mRNA to translate and produce proteins
what is messenger RNA (mRNA)
records the DNA’s nucleotide order, bringing specific nucleotide orders to ribosomes, contains the information for genes
what does a chain of amino acids form?
a protein
