Module 1 Flashcards
study guide
Organelles: nucleus
(the “recipe book”)
consists of: nuclear envelope, nucleoplasm, nucleolus, and chromatin
the control center housing genetic material
regulates cell activities through gene expression
nucleolus is responsible for ribosome production
organelles: mitochondria
(the power house of the cell)
consists of: double membrane with inner membrane forming christae (folds)
energy production (ATP) thru cellular respiration
plays role in apoptosis
have own DNA which supports endosymbiotic theory
organelles: cell membrane
(the cell bouncer)
consists of: phospholipid bilayer with embedded proteins, cholesterol, and carbs
facilitates communication via receptors and channels
protects cellular integrity
organelles: endoplasmic reticulum
(the “production” factory)
consists of a network of membrane-bound tubes and sacs
transport and synthesis of molecules
two subtypes:
smooth: lacks ribosomes, involved in lipid synthesis and detoxification
rough: studded with ribosomes, involved in protein synthesis
organelles: golgi apparatus
(the “Amazon” of the cell)
consists of stacks of flattened cisternae (membrane bound sacs)
modifies, sorts, and packages proteins and lipids for transport to their destination
produces lysosomes
works closely with ER to process and package proteins
organelles: lysosomes
(the “lysol/mr clean” of the cell)
consists of membrane bound vesicles containing hydrolytic enzymes
breaks down waste, damaged cell parts and invading pathogens
involved in apoptosis
role in maintaining cellular health by removing debris
organelles: ribosomes
consists of small, non-membrane bound organelles made of RNA and proteins
found in rough ER or free in cytoplasm
sites of protein synthesis (translation of mRNA into polypeptides)
role in gene expression and cellular function
organelles: cytoplasm
gel-like fluid where organelles are suspended. allows for the movement of materials within the cell
organelles: cytoskeleton
network of protein filaments and tubules that provide structure and aid in movement
organelles: vacuoles and vesicles
vacuoles: larger in plant cells but present in human cells for storage
vesicles: small membrane-bound sacs that transport materials within the cell
function: storage and transport of nutrients, waste and other materials
endocytosis
the process of bringing a substance into the cell that is too larger to enter by other mechanisms. the cell membrane surrounds the particles, engulfing them
phagocytosis
cell eating - endocytosis of a solid particle
pinocytosis
cell drinking - endocytosis of a liquid
exocytosis
the release of materials from the cell onto the cell membrane, usually with the assistance of a vesicle. examples of substances secreted by exocytosis: albumin, immunoglobulins and hormones.
diffusion
the movement of solutes from an area of higher concentration to an area of lower concentration (can be simple or facilitated) example - gases in the lung are exchanged by diffusion
simple diffusion
diffusion that requires no energy or the use of transport proteins. examples: small, nonpolar, and hydrophobic particles like oxygen and carbon dioxide
facilitated diffusion
diffusion that requires no energy but does use transport proteins (channel or carrier) to move substances from higher concentration to lower concentration. example: water is small molecule, but polar so it requires a channel
osmosis
the movement of water or any other solvent across the cellular membrane from an area of low solute concentration to an area of high concentration (water wants to dilute solutes) this allows cells to stay hydrated. passive transport. osmotic pressure refers to solute concentration (ie high solute concentration=high osmotic pressure)
active transport
the movement of a substance from an area of lower concentration to an area of higher concentration. energy in the form of ATP is required to go against the gradient
Primary - uses energy directly from ATP ie sodium-potassium pump, calcium pump, and proton pump
secondary - stored energy from the sodium-potassium pump is used by other molecules such as glucose and calcium. neurotransmitters also use secondary active transport.
osmolarity
number of milliosmoles of solute in 1L of solution. amount of solutes in a solvent. ie high osmolarity=high concentration of solutes, low osmolarity=low concentration of solutes. preferred term for fluids outside the body ie IV fluids
osmolality
number of milliosmoles of solute in 1kg of solvent. preferred term when referring to fluids inside the body. ie a serum level
apoptosis
programmed cell death; occurs when cell division stops and growth ceases. triggered by the telomere reaching a particular length (telomeres are essentially a biological cell timer)
mitosis
Interphase: spends 90% of its time here (growth, DNA replication, cell function)
Prophase: condensing chromosomes in the nuclease
Metaphase: “middle” chromosomes lined up in the middle (no more nucleus)
Anaphase: 1/2 chromosome pulled by spindles away from center towards the centrioles
Telophase and cytokinesis: nucleus forms around each half of chromosomes and cytokinesis is when cells separate into two daughter cells, each containing a copy of the same chromosome
chromosome
consists of DNA and histone and non-histone proteins, packages of information in the nucleus, attached by centromere
histone
proteins that are basically the spools around which DNA wraps itself
chromatid
each of the separate identical copies created when the chromosome replicates; they attach to each other through a centromere
nucleotides
basic building blocks of DNA and RNA consists of pentose sugar molecules, phosphate (ladder’s sides) and 1 of 4 nitrogen containing bases
DNA
double stranded, contains deoxyribose sugar ATCG, stores genetic info
RNA
single stranded, contains ribose sugar AUCG (uracil replaces thymine), protein synthesis
nucleosome
a segment of tightly coiled DNA wrapped around a collection of histone proteins; the fundamental unit of chromatin
chromatin
DNA that is combined and wrapped around the histone proteins
base pair
nitrogen bases (steps) of nucleotide are either purine (adenine and guanine) or pyrimidine (thymine and cytosine)
gene
segment of DNA that codes for a protein or function. a gene refers to the trait
allele
a version of a gene. an allele refers to the variant of the gene
epigenetics
explains how environmental factors can alter gene expressionwithout altering underlying DNA sequence. Plays a significant role in development, disease, adaptation, and physical development.
methylation of DNA can turn genes on or off which regulates production of proteins (stops transcription).
histone changes also stop transcription
mitochondrial (cytoplasmic) inheritance
traits passed through mitochondrial DNA from mother to offspring. only moms can pass (ie leber’s hereditary optic neuropathy)
x-linked recessive
single gene disorder. recessive allele on x chromosome, affects males more than females. affected males only pass to daughters (ie hemophilia, duchenne muscular dystrophy)
x-linked dominant
dominant allele on x chromosome. more females affected but it’s more severe in males. affected males pass to all daughters but not sons (ie fragile x)