1: Cell Physiology Flashcards
Common shared features of cells
size, shape, and structure
functional unit of the body
organ
feature of a prokaryote
lacks nucleus and some organelles
feature of a eukaryote
nucleus separated by nuclear membrane
composition of cilia
tubular proteins
what allows cilia or flagella to move, bend
sliding of microtubules
give two examples where cilia is found
upper respiratory tract (to trap and remove dust, mucus, and secretions)
fallopian tube (to assist the egg through the oviduct) and epididymis in males
living components of the cell
organelles
identify the similarities in eukaryotes and prokaryotes
see module
identify the differences
see module
list the nonmembrane-bound organelles (4)
ribosomes, microtubules, microfilaments, and intermediate filaments
list the membrane-bound organelles (6)
nucleus, mitochondria, endoplasmic reticulum, lysosomes, perixosomes, and golgi apparatus
two components of the cell
cytoplasm and nucleus
information and administrative center of the cell
nucleus
gelatinous solution containing the organelles
cytoplasm
the fluid part of the cytoplasm
cytosol
refers to substances that make up the cell
protoplasm
composition of the cell
70-85% water
10-20% protein
1-2% carbohydrates
water
70-85% of the inner cell mass
principal fluid medium of the cell
functions of water (5)
- solvent for ions and macromolecules
- as chemical reactant (hyrdrolysis)
- medium for transport (blood, bile, urine, milk)
- as lubricant in joints
- regulates body temperature
inorganic substances needed for cellular reactions
electrolytes
most important electrolytes in the cell (8)
K, Cl, Ca, PO4, Mg, HCO3, Na, SO4
two types of proteins in the cell according to structure
structural protein -linear proteins like cytoskeleton proteins (microtubule, microfilaments, intermediate filaments)
globular protein - like enzymes
structural proteins diagram
see module
2 types of proteins in the cell according to composition
simple proteins - albumins, globulins (in blood), protamines, histones, albuminoids (in cells of tissues)
- composed of amino acids
conjugated proteins - glycoproteins, lipoproteins, nucleoproteins, chromoproteins (ions), metalloproteins, and phosphoproteins
- with non-amino acid components
describe lipids
- mass in the cell:
- composition:
- function:
2% of the inner cell mass
consist primarily of C, H, O2
- forms cell and intracellular membranes that separate the different cell compartments
- animal cells have cholesterol (stores in the blood and liver)
carbohydrates
- mass in the cell:
- types of carbs
1% of the inner cell mass
a. monosaccharides - glucose, galactose, fructose
b. disaccharides - sucrose, lactose, maltose
c. polysaccharide - glycogen
stored insoluble form of glucose in the liver and skeletal muscle cells
glycogen
describe the nucleus
- relative size
- parts
- largest single organelle
- nuclear membrane, nucleolus, nucleoplasm, chromatin
bilayered membrane with gaps called nuclear pores that allow the transport of ions and small molecules like mRNA in and out of the nucleus
nuclear membrane/envelope
soluble liquid form of nuclear material not occupied by nucleolus or chromatin
nucleoplasm
- 1-4 RNA-containing bodies in the nucleus
- site of ribosome synthesis!!!
- produces rRNA (and packaged with proteins to form ribosomal subunits and exported to the cytosol via the nuclear pore complexes)
nucleolus
carries DNA and occur sin pairs except in germ cells
chromatin
two types of chromatin and their differences
a. heterochromatin - condensed or clumped, metabolically active
b. euchromatin - dispersed, singly, and replicating
- site of key biochemical processes for ATP production in the cell
- double membrane with inner membrane folded to form the CRISTAE
- site of Kreb’s or TCA Cycle and Cellular respiration (ETS - electron transport system)
mitochondria
cells that lack the mitochondria
RBCs
describe the mitochondrial matrix
- dense with DNA (smaller than those in the nucleus), large phosphate granules and ribosomes that are smaller than cytoplasmic ribosomes
- contains enzymes for the Kreb cycle and beta oxidation of fats (usually in liver cells)
inner membrane of the mitochondria
- has enzymes for oxidative phosphorylation
- electron carriers for the ETS
- has the F1 factor or ATP synthase during cellular respiration
outer membrane
- outer covering of the mitochondria
small, spherical membrane-bound organelles
vesicles
3 types of vesicles
a. lysosomes
b. peroxisomes
c. secretory vesicles
describe the lysosomes
- function
- condition to work
- suicide bag of the cell
- digests food vacuoles or degenerating organelles of the cell through 40 hydrolytic or digestive enzymes
- enzymes thrive in acidic medium (pH 3.5-5.0) (more H ions) (note: cytoplasm has neutral pH)
- lysosomal membrane protects the cell from the enzymes
where are lysosomes formed?
golgi apparatus
4 lysosomal enzymes
lipase, carbohydrases, proteases, nucleases
lysosomal enzymes engluls (endocytosis) and cause autolysis of:
a. degenerating components - autophagic vacuole
b. bacteria or foreign substances - phagocytic vacuole
other functions of lysosomes
a. destroy RBC and dead cells
b. dissolution of blood clots and thrombi
c. keratinization of skin
d. secretes hydrolases by sperm for penetration of ovum
e. digestion of yolk
f. bone resorption
g. defense against invading organisms by circulation macrophages (heterophagy)
small membrane-bound vesicle containing oxidative enzymes for very long chain fatty acids
- generation and destruction of hydrogen peroxide
peroxisomes
3 peroxisomal enzymes
a. catalase - for oxidation (production of hydrogen peroxide, H2O2, which can cause cell death) and peroxidation reactions (destruction of hydrogen peroxide with the formation of water)
b. urate oxidase
c. D-amino oxidase
oxidation: RH2 + O2 = R = H2O2
peroxidation: H2O2 + R’H2 = R + 2H2O
!!! oxidation: generation of hydrogen peroxide
peroxidation: destruction of hydrogen peroxide
- vesicles that store secretions
- site formation: ER-Golgi apparatus system
secretory vesicles
how are secretory vesicles released outside the cell
exocytosis
complex series of tubules in the cytoplasm
endoplasmic reticulum
- site of protein synthesis for extracellular use like hormones
- continuous with the outer nuclear membrane because this is where mRNA goes for translation
- more extensive
RER or Granular ER
- round tubules, lacks ribosomes
- site of lipid synthesis!!!
- site of processing synthesized proteins and detoxification of foreign substances
smooth ER or Agranular ER
describe ribosomes
- function
- site of synthesis
- composition
- sub-units
- site of protein synthesis
- site of synthesis: nucleolus
- 65% RNA and 35% protein
- prokaryotes: 50s, 30s ; eukaryotes: 60s, 40s
2 types of ribosomes in the cell and their description
a. free ribosomes - in cytoplasm, linked together in chains or polysomes, site of protein synthesis for intracellular use (hemoglobin etc.)
b. bound ribosomes - attached to ER, singly, site of protein synthesis for extracellular use ( e.g., hormones)
- stacks of 5-8 membrane-enclosed sacs called “cisterns”
- produces lysosomes
- processing of macromolecules from SER
golgi apparatus
parts of the polarized structure of golgi apparatus
a. cis face - forming phase, transport vesicles are formed from ER, where immature protein enters
b. trans face - maturing phase, where secretory granules are formed and mature proteins exits
components of the cytoskeleton
a. microtubules - largest
b. intermediate filaments - medium
c. microfilaments - smallest
in prokaryotes: actin, flagellin, tubulin
describe microtubules
- morphology and composition
- distribution
- arrangement
- long, hollow structure made up of alpha and beta tubulin subunits
- from centrioles and distributed in the cytoplasm
- arranged in singly, doubly (cilia and flagella), and triplet (centrioles and basal bodies)
list the functions of microtubules
a. mechanical and structural function
b. placement and movement of organelles (prevents them from bumping and therefore, from damage)
c. cell division (mitotic spindle)
d. main component of cilia and flagella
e. cellular motility or movement
f. transport macromolecules within the cell
- site of microtubule production
- made up of 9 sets of triplet microtubules that are radially arranged (27 all)
- near the nucleus
centrosome
composition of centrosome
centrioles and amorphous pericentriolar material
- long projections at the cell apex
- transport materials along cell surface
cilia
two types of cilia
a. kenocilia - true cilia, motile
b. stereocilia
- short projections
- for motility of sperm as its tail
flagella
- most abundant and stable component of the cytoskeleton
- most important filamentous component in the matrix of the cytoplasm
- impt to nuclear membrane and cell membrane
intermediate filaments
major mammalian intermediate filament proteins
see module
functions of intermediate filaments
a. bears tensions on tissues (mechanical strength)
b. anchors cytoplasmic organelles
- at the periphery and apex of cells
- solid rod made of globular proteins called actin (nonmuscle cells) and myosin (muscle cells)
microfilaments
2 types of microfilaments in nonmuscle tissues
a. G-actin monomer
b. F-actin monomer
functions of microfilaments
a. mechanical and structural support
b. formation of cytoplasmic protuberances
c. cytokinesis
d. muscular contraction!!
- semi-permeable lipid bilayer containing proteins and CHO (carbs) that surrounds the cell
cell membrane
functions of the cell membrane
a. transport of substances
b. protection
c. enzymatic activity
d. intercellular communication and recognition
e. coordination of extracellular changes
components of cell membrane
55% protein
42% lipids
3% carbohydrates
3 components of cell membrane lipids
phospholipids, cholesterol, and glycolipids
see module for full content
what does the hydrophylic end do in the cell membrane?
- exposed to the aqueous environment that bathes the cell exterior and cytoplasm
what does the hydrophobic end do in the cell membrane?
- meets the water poor interior of the cell
- important in preventing escape of most of the water soluble substance in the cytoplasm
see module for diagram
what maintains the fluidity of the cell membrane especially at low temperatures?
cholesterol in the CM phospholipids
sugar containing lipids located in the outer CM
glycolipids
explain the importance of CM fluidity
important for the CM to function effectively in the entry or exit of substances
factors maintaining CM fluidity
a. presence of cholesterol among CM phospholipids
b. increase in unsaturation of fatty acid during low environmental temperature (increases the kinks in CM)
c. movement of CM phospholipids (lateral shift, transverse, and longitudinal)
extensive cell coat found on special surfaces
glycocalyx
- responsible for the functional behavior of the CM
CM proteins
2 types of CM proteins
a. intrinsic proteins - integral, penetrating, or transmembrane protein
- alpha-helix protein
b. extrinsic proteins - loosely bound, peripheral or surface-located protein
- can form glycoprotein with CHO
