Cell Structure, Function, Organization Flashcards
eukaryote
What cells require alot of energy in the body to function? What organelle does this type of cell have the most of?
- skeleal muscle cell, neuronal cells
- mitochondria
eukaryote
What is found inside the nucleus?
- DNA (contains genes that will code for proteins), which are stored in chromosomes, which are highly condensed chromatin
- nucleolus: makes rRNA and ribosomes
remember: PROKARYOTES have NO nucleus, so the DNA and ribosomes are just free floating in the cytoplasm.
eukaryote
What processes occur in the nucleus?
DNA replication and DNA transcription into mRNA
eukaryote
Where does translation occur?
cytoplasm of the cell (done by ribosomes that are free (unbound) or bound to the rough ER)
What type of cells have alot of golgi?
secretory cells (ie. salivary gland cells)
Compare prokaryotes and eukaryotes aka what are the SIMILARITIES
- cell/ plasma membrane
- cytoplasm
- cytoskeleton
- DNA and ribosomes
Contrast prokaryotes and eukaryotes aka what are the DIFFERENCES
- nucleus status
- membrane organelle status
- mechanism of replication
biological hierachy
List the components of the biological hierachy from least to most complex
- chemicals: atoms –> moleulces –> macromolecules –> organelles (structures that allow for cell survival)
- cell = building block of a living organism
- tissues (groups of cells with similar function) - 4 types (epithelial, connective, muscle, nervous)
- organs
- organ systems
- organism
What are the 4 types of tissues?
- epithelial
- connective
- muscular
- nervous
Describe epithelial tissue (where is it found, characteristics of it)
- found in the lining of GI tract and other hollow organs (ie. respiratory tract and endothelium of blood vessels) and also the skins epidermis
Characteristics:
* Avascular and gets its nutrients from underlying basement membrane of connective tissue
* glandular (ie. oil secreted from skin and digestive juices from GI tract organs)
* named based on shape and arrangement (shape: squamous- flat, cuboidal, columnar- long); arrangement (simple- single layer of cells, pseudostratified- looks like multiple layers of cells BUT is not, stratified- multiple layers of cells)
Examples
* simple squamous (thinnest of the thin) - optimal for gas and nutrient exchange ( found in alveolar membrane of lungs and endothelium of blood vessels)
* simple columnar - lining of GI tract and fallopian tube
* stratified squamous - good for areas that get lots of friction (ie. epidermis of the skin, mouth, esophagus)
Describe connective tissue (where is it found, characteristics including function and what it’s made of)
- found throughout the body EXCEPT for the brain
Examples
* 3 fascial layers of the muscle (epimysium , perimysium, endomysium)
* tendons and ligaments (dense CT with LOTS of collagen)
* cartilage (made by chondrocytes)
* osseus tissue (bone tissue) made of osteocytes (mature bone cells) + bone matrix (INorganic Ca salts embedded into ORganic collagen fibers)
* adipose tissue (made of fat cells)
* blood (formed blood cells and plasma)
Characteristics
* HIGHLY vascular EXCEPT for tendons, ligaments, and cartilage
* funtion: protect and support the body
* made of ground substances- water, proteins, carbs- and protein fibers - COLLAGEN (MAIN one), elastin, reticular
Describe muscular tissue (where is it found)
- cardiac: heart myocardium
- skeletal: skeletal m. (when it contracts, it pulls the bone under it and moves it and so moves the entire body)
- smooth: generates the WEAKEST contractions bc of NO striations , so is present in the internal organs
Describe nervous tissue (where is it found)
- CNS- brain and spinal cord
- PNS- all the peripheral nerves (going to and from the brain via CN and the spinal cord via spinal nerves)
Note: NS comes from ECtoderm EXCEPT the CNS’s microglial, resident macrophages, come from MESODERM.
give an example of least to most complex of the biologial hierachy
lipids (macromolecule) –> neuron (cell) –> gray matter (tissue) –> brain (organ) –> CNS (organ system)
give an example of least to most complex of the biologial hierachy
lipids (macromolecule) –> neuron (cell) –> gray matter (tissue) –> brain (organ) –> CNS (organ system)
What organisms contain a cell wall?
plants, SOME bacteria, and fungi- yeast
animal cells and protists DO NOT have a cell wall & SO IS MORE FLEXIBLE
Contrast plant cells and animal cells
Animal cells - have centrosomes , NO cell wall
Plant cells- have all things animal cells BUT also contain a cell wall, chloroplasts carrying out photosynthesis (using sun light energy to generate glucose as food source), central vacuole (stores, water and glucose)
protists ALSO have NO CELL wall
What are the 2 prokaryotes?
bacteria and archae
What are the eukaryotes?
plants, animals, fungi-yeast, protists aka protozoans
The method of binary fission to replicate is asexual or sexual?
asexual (done by prokaryotes)
What is the purpose of the cell wall?
protect and support the cell and provide cell shape in plants, SOME bacteria, fungi- yeast
What does the cell/ plasma membrane divide?
inside of cell from outside environment
Describe the permeability of the cell membrane
selective permeability - small, NON polar (hydrophobic, water INsoluble) items are able to freely cross the membrane (ie. simple diffusion of gases like O2 and CO2) while large, POLAR (hydrophilic, water SOLuble) substances aren’t. (this is the door to the cell)
What is passive transport? What are the 3 major types?
taking a substance from HIGH to LOW concentrations (DOWN the concentration gradient) , so requires NO ATP (energy)
- simple diffusion of small, NONpolar (uses NO channels) ie. of O2 and CO2
- facilitated diffusion of large, POLAR (USES channels) ie. water aquaporin channels inserted by ADH/ vasopressin, glucose channels inserted by insulin, voltaged GATED Na and K channels)
- osmosis = diffusion of water from high to low concentration (either simple or facilitated through aquaporin channels)
Where is Na and K usually found (inside or outside the cell)? What maintains this gradient?
- Na: OUTSIDE the cell (think salt rim of a marg) - serum Na is 135-145
- K: INSIDE the cell- serum K is 3.5 -5.1
- Na/ K ATPase maintains this by pumping (3 Na OUT and 2 K IN)
very important for electrical impulse (AP ) conduction down axon, muscle contractions
What happens when voltage gated Na and K channels are open
- Na channels open = Na diffuses INTO the cell –> depolarize –> (skeletal m. contracts)
- K channels open = K diffuses OUT of the cell –> repolarize or hyperpolarizes (ie. dec contraction of cardiac m. cells)
going DOWN concentration gradient
What is active transport? What are some examples?
taking a substance from LOW to HIGH concentrations (against the concentration gradient), so it REQUIRES ATP (energy)
examples: Na/ K ATPase (pumps 3 Na + OUT and 2 K+ IN to the cell) , endo/ exocytosis (requires energy BUT doesn’t necessarily go against the conc. gradient)
Osmosis is what type of transport (active or passive)?
passive transport of water from high to low cocentrations so does NOT require energy
What is the normal resting membrane potential of the plasma membrane?
negative
What is the cell/ plasma membrane made of? What are other components embedded in the plasma membrane?
phospholipid BIlayer of polar (hydrophilic) head and NONpolar (hydrophoboic) fatty acid tails , which can be saturated (more stable) or unstaurated (more flexible).
embedded: integral proteins (glycoproteins- antigens= ID tags; transmembrane that span both layers, which can act as enzymes or receptors, which when activated will open channels to let substances in or out, trigger endocytosis, or do cell signaling.
What is an example of a glycoprotein?
antigen (ID’s the cell)
What is the function of ribosomes? What are the types in eukaryotes and prokaryotes and explain?
- turn mRNA into protein through translation
- in eukaryotes, there are two types: free (unbound) in the cytosol and rough ER bound ones
- in prokaryotes, there are only free ribosomes floating in the cytoplasm
eukaryote
What type of proteins do the free ribsomes in the cytoplasm create ?
proteins that STAY in the cytoplasm
eukaryotes
What type of proteins do ribosomes bound to the rough ER create?
- integral proteins that become ID of the cell (ie. antigen) OR channel protien
- secretory proteins (enzymes or hormones secreted OUT of the cell)
ER
What is the function of the rough ER? What is the function of the smooth ER?
- rough ER: fold and (some modification) and transport PROTEINS
- smooth ER: make lipids (phospholipds, cholesterol) for the plasma membrane or synaptic vesicles for example
both proteins and lipids are put into vesicles to go to golgi to be modified.
What is the smooth ER called in muscle cells? What is released from the said structure?
sarcoplasmic reticulum and contains Ca, which when released will cause muscle contraction
more SR is found in skeletal muscle.
What is the function of the Golgi?
“Fed - Ex of the cell”
* modify, sort, package into vesicle and ship the modified lipid/ protein out
* modifications: sugar added to lipid –> glycolipid ; sugar added to protein (glycoprotein); lipid added to protein (lipoprotein)
* ship: glycoproteins and lipoproteins can be: exocytosed out of the cell, integrated into the plasma membrane as a glycoprotein antigen to ID the cell or become a channel protein (and pretty much same with the glycolipid)
What face of the golgi recieves the vescile from the ER? What face of the golgi ships out the vescile from the golgi?
cis , trans
What is the function of the mitochondria?
“Power house of the cell”
* makes ATP (when oxygen is present), which is the cells energy source through cellular respiration, which extractions the energy from CARBON broken bonds
In the most general of ways, how is ATP made ie. what type of bonds are broken?
extraction of energy from broken CARBON bons
What are some energy sources that can be used to generate ATP in the mitochondria?
- glucose
- AA
- FA
- ketones, which can be a sub for glucose (come from fatty acids)- remember diabetes can cause DKA bc insulin is not working to bring glucose into the cells to be converted into fuel, which is sensed by the liver, so it starts making ketones and pushes into the blood, and if there is too many ketones, can lead to metabolic acidosis bc ketones are acidic.
What is required for the mitochondria to carry out cellular respiration? What is this type of respiration called?
O2, AEROBIC respiration
Where does glycolysis take place? Does it require O2?
cytoplasm, NO O2 (anaerobic respiration) required so good for sprinting
Explain cellular respiration
in ipad
What are the byproducts of cellular respiration?
- lactic acid through fermintation if there is not enough O2, which is acidic and in the blood tingles the nerves leading to “ feel the burn” sensation
- CO2 from the citric acid cycle/ TCA/ kreb cycle , which will ultimately be exhaled out.
What are the 4 general steps to cellular respiration?
- glycolysis
- citric acid/ kreb/ TCA cycle
- ETC
- oxidative phosphorylation
Where is most ATP produced?
inner membrane of the mitochondria (cristae) via chemiosmosis when there is O2 present
Describe the cytoskeleton (what is it made of in general, what are the different components?)
- made of a bunch of protein fibers
Components
* actin- for cell shape (present in microvilli of intestinal cells, dendrites and axon terminals of neuronal cells) AND also interacts with myosin in order to contract muscle
* microtubules - THICCEST component of the cytoskeleton for cell movement (helps move items within the cell and the whole cell itself) (mlcr motors ie. kinesins with vesicles attached use microtubules as a railway to move the bound item within the cell) (ie. flagella helps move the whole cell) (microtubules make up the spindle fibers and centrioles and centrosomes that are involved in pulling sister chromatids and homologous pairs apart in cell division)
* secures the organelles into place
What is the function of the lysososome?
breakdown old cell debris via hydrolytic enzymes present in it
* pH is low to allow for optimal enzyme function.
What is Tay Sach’s dz?
mutation in the hydrolytic enzymes in the lysosomes
What is the function of vacuoles?
- storeage of water and food for survival and transport
- digestion - in plant cells
- waste removal
remember- plant cells have a large central vacuole holding water and sugars
What is the function of chloroplasts? Where are they found?
- take suns light energy to convert it into sugars (flip of the cellular respiration equation) via chlorophyll
- in plant cells
Compare and Contrast photosynthesis and cellular respiration
- flip of each others equation
- photosynthesis ONLY happens in plant cells
What is generally happening in interphase?
cell is growing and DNA is duplicating
When does interphase occur?
right before mitsosis and right before meiosis ONE (NOT present b/w meiosis one and two)
What are the 3 parts of interphase and describe them. What is the general condensation status of the chromosomes, status of nucleolus and nuclear envelope?
- G1 - cell is growing and everything BUT DNA is duplicating (ie. organelles, centrosomes) and getting ready for DNA replication (mRNA, tRNA, rRNA, enzymes) - HAS THE MOST NUMBER OF NUCLEOTIDES TO PREP FOR DNA REPLICATION IN S PHASE
- S- synthesis (DNA replication occurs ) (2n –> 4n)
- G2- preparing for cell division (organelles keep diving, proteins keep synthesizing)
checkpoints are also present (if don’t pass G1 checkpoint, then get into G0 phase where if the issue can’t be corrected, the cell will go through apoptosis)
chromsomes are still condesned, nuclear envelope and nucleolus are still present
What is the normal n in human cells? Explain 2n
23 (meaning we have 23 unique chromomsomes and 23 homologous pairs); we have 2 copies of the 23 unique chromomes, one copy from mom and one copy from dad, leading to a total of 46 chromosomes
we normally have 2 copies of each chromosome
What cells are ALWAYS in the G0 phase?
neuronal cells and cardiac muscle cells
What is generally happening during mitosis?
nuclear division, NO MORE growing
Contrast mitosis and meiosis
Mitosis
* (one parent cell) produce 2 genetically IDENTICAL daughter cells , which are DIPLOID (2n) [ 4n –> 2 n]
* somatic and germ cells can go through this (BUT somatic cells ONLY go through mitosis)
Meiosis
* produce 4 genetically UNIQUE cells, which are HAPLOID (n)
* undergo TWO rounds of division : meiosis 1 [ 4n –> 2n] and meiosis 2 [ 2n –> n]
* ONLY happens in germ cells of the gonads (ovaries and testis) to produce sex cells aka gametes, which are the sperm and egg
* after fertilization is when sperm (23 chromosomes) and egg (23 chromosomes) combine to make a zygote (fertilized egg) to regain normal chromosome number of 46 and diploid status
Explain mitosis
- P- chromatin condense into tighly coiled chromosomes aka chromosome condenses, nuclear envelope dissapears, nucleolus dissapears
- prometaphase- kinetochores form at centromeres of sister chromatids, which is where the spindle fibers will attach
- M- sister chromatids line up at Middle and spindle fibers attach
- A- sister chromatids are pulled Apart
- T- chromosomes decondense, nuclear envelope reappears, nucleolus reforms, spindle fiber degrades
- cytokensis: actual cytoplasm separation and form 2 genetically identical daughter cells
Is DNA replication happening between meiosis 1 and 2?
NO, there is NO interphase
What is unique about meiosis 1?
during prophase 1 there is crossing over at the chiasmata of the homologous chromosome pair to increase genetic diversity
What type of cells are constantly dividing?
epithelial cells that are lining GI tract, respiratory tract, and found in the skin epidermis
What type of cells are rarely dividing?
- chrondrocytes, which make cartilage
- fibroblasts, which make tendons and ligaments
that’s why it takes so long to repair a bone fracture (3-4 years for complete healing)
centromere vs centrosome
- centromere: protein that attaches sister chromatids
- centrosome: houses the centrioles that spindle fibers come from
Explain the anaphase of meiosis 1 and meiosis 2
- meiosis 1: homologous pairs are pulled apart
- meiosis 2: sister chromatids are pulled apart (most similar to mitosis)
What type of tissue is bone?
connective tissue
What type of organisms participate in photosynthesis and what organisms participate in oxidative respiration
- photosynthesis: many prokaryotes (ie. bacteria) and eukaryotes (ie. plants and some protists)
- oxidative respiration: AEROBIC prokaryotes AND EUKARYOTES
During cytokinesis, what does plant vs. animal cells do?
- plant: forms a cell plate bc it has a cell wall
- animal: forms a cleavage furrow bc has NO cell wall
Glandular epithelium can secrete what?
hormones, oils, digestive enzymes
