ap bio chpt 4

personal flashcards, notes from textbook

cell theory

cells r the basic units of structure and function in an organism, all organisms are composed of cells, they come from preexisting cells cuz they r self-reproducing.

cellular malfunction some results:

diabetes, prostate cancer

how does a single cell organism reproduce? how abt multicellular?

binary fission: a single cell divides and becomes 2 new organisms. multicellular organisms reproduce by many cells divi

prokaryotic v.s eukaryotic cells size:

1-10 um(micrometers). 10-100 um

why are cells so small?

to maximize the ratio of surface area to volume, which helps them function.

what does being small help cells mainly do?

exchange materials, eliminate waste products, and acquire/dissipate thermal energy

cuz cells r so small, sometimes they can only be seen with-

special microscopes

what type of cells are humans built out of?

eukaryotic cells

the organelles in eukaryotic cells r about the size of:

prokaryotic cells

what does increasing surface area in a cell do?

increases ratio, increasing diffusion/exchange

what does decreasing surface area in a cell do?

decreases ratio, decreasing diffusion/exchange

what is an example of the surface area-volume ratio size in the real world?

think of opening a can of Axe body spray in a gymnasium, vs classroom, vs elevator. just like the size of the space affects how quickly a spray disperses, the size of a cell affects how efficiently it can manage its internal processes.

so in conclusion, a small cell is more efficient in:

transporting materials in and out/exchanging molecules.

what modifications help increase over all surface area of a cell?

folds.

what is the in-fold modification called?

mesosomes

what is the out-fold modification called?

microvilli

what is a real life example of these in-folds and out-folds?

elephants v.s whales: we spread out to catch cool air, we curl in during the cold to preserve body heat.

what is a compound light microscope?

uses glass lenses to focus light rays passing through a specimen to produce an image that is viewed by the human eye.

what is a TEM? (transmission electron microscope)

uses electromagnetic lenses to focus electrons passing through a specimen to produce an image, which is projected onto a fluorescent or photographic film.

what is a SEM? (scanning electron microscope)

uses a narrow beam of electrons to scan over the surface of a specimen that is coated with a thin metal layer. the secondary electrons given off by the metal are detected, and used to produce a 3-D image on a TV screen.

what is magnification?

the ratio between the size of an image and its actual size.

what is resolution?

the minimum distance between 2 objects that allows them to be seen as 2 separate objects. with a good microscope, you will be able to see the resolution (instead of just one object with a bad microscope.)

what is contrast?

a difference in shading of an object compared to its background. the ability to make out, or resolve, a particular object depends on this.

surface area of a cube formula:

SA= 6s²

volume of a cube formula:

V= s³

3 main facts of prokaryotic cells:

1. lack a nucleus

2. smaller in size (about size of eukaryotic organelle)

3. 2 different domains: bacteria and archaea.

prokaryotes as a group r the most abundant diverse life-forms on earth. they are present in:

air, water, soil, organisms, etc.

prokaryotic v.s eukaryotic cells size real life comparism:

prokaryotics r simple, like a 1 room apartment or store. eukaryotics r huge and complex, like a mansion or a mall.

what is the innermost layer of a prokaryotic cell?

cell membrane (or plasma membrane) decides what goes in and out of the cell (common to all cells)

what is the middle layer of a prokaryotic cell?

cell wall, made out of peptidoglycan, maintains shape and protects cell (example: intake of water no matter how much, or invaders)

what is the outermost layer of a prokaryotic cell?

glycocalyx is a layer of polysaccharides that serves as a barrier and can be a capsule (if organized) or slimy (if not).

what does the glycocalyx do?

it helps the bacteria resist a host’s immune system and aids against drying out. it also helps bacteria attach to almost nay surface.

what are the hairlike structures called?

fimbriae. they are hairlike bristles that allow adhesion to surfaces. they also contain conjugation/sex pilli, which are tubes used to pass DNA from cell to cell.

prokaryotes do binary fission, which is ______, but they also can exchange DNA using the fimbriae.

self reproduction/ reproducing asexually.

what are appendages?

structures that extend from main body/body parts, examples: fimbriae, flagella, sex pilli, etc.

what does the flagella do?

whip-like tail, helps with movement.

what is the cytosol?

semifluid solution composed of water and inorganic and organic molecules encased by the plasma membrane. among the organic molecules r a variety of enzymes.

what are enzymes?

they speed up chemical reactions involved in metabolism.

what is the nucleoid? what is in it?

prokaryotes lack a membrane-bound nucleus, so they have this. it is the location of the singular chromosome and its DNA.

what are plasmids?

circular pieces/small accessory rings of DNA, not found in the nuceliod but more in the general cytosol.

what is a ribosome?

workbench for/site of protein synthesis, found in cytoplasm of a prokaryotic cell.

what is cytoplasm?

everything inside the cell membrane, including the cytosol and organelles.

what is the cytoplasm of a prokaryotic cell?

cytosol, nucleoid, plasmids, and ribosomes.

what is cyanobacteria? (poster child for bacteria)

form of bacteria that is responsible for a lot of oxygen in our enviorment, capable of photosynthesis, and their cytoplasm contain thylakoids.

how does cyanobacteria produce/release oxygen?

cuz its a by-product of the photosynthesis they conduct.

what are thylakoids?

membrane-bound structures found within the chloroplasts of plant cells and in the cyanobacteria, crucial for photosynthesis.

how do some(not all!) prokaryotes carry out metabolism?

the same way as animals: by ingesting other organisms.

what is nitrogen fixation?

takes nitrogen and changes it into a form where plants can use it. cyanobacteria does it.

what is the archaea domain evolve from? (even though its name means ancient)

it evolved from the bacteria domain!

what are the inner parts of archaea?

cytosol, nucleiod, ribosomes, plasmids.

what is a archaea cell wall contain?

polysaccharide! (instead of peptioglycan in a bacteria cell wall)

what are the archaea cell membrane made up of?

hydrocarbons (instead of fatty acid chains)

what is the main unique quality of an archaea?

they are extremophiles, so they can live in harsh conditions such as hot weather, high pH, and more due to adaptations

what is the DNA and RNA structure more similar to in archaea?

its similar to eukaryotes.

what are the 3 domains in the whole world?

bacteria, archaea (<—these 2 r prokaryotic cells), and eukarya (<—plant n animal cells are this). these are all split into more kingdoms.

linnaean classification of life: dear king phillip came over for good soup

domain, kingdom, phylum, class, order, family, genus, species.

what are the eukaryotic kingdoms?

fungi, animalia, plantae, protista.

what is the fungi kingdom?

heterotrophs that absorb their nutrients - mostly multicellular and have cell walls built of chitin.

what is a heterotroph? what about autotrophs?

they get the energy they need to live from other organisms. autotrophs can produce their own food. example: plants do photosynthesis to produce their own food.

what is the animalia kingdom?

they are ingestive heterotrophs. we are in it.

what is the plantae kingdom?

they use photosynthesis.

what is the protista kingdom?

eukaryotic cells (usually unicellular) - can be heterotrophs or autotrophs

what are the 5 main facts of eukaryotic cells?

1. members of the domain eukarya.

2. has membrane-bound organelles.

3. larger, so less surface area per volume.

4. compartmentalized (has organelles that perform certain funtions).

5. plants have cell walls made of cellulose.

what is the endosymbiotic hypothesis/theory?

states that mitochondria and chloroplasts used to be free living prokaryotes, but eventually went to live inside a larger eukaryotic cell. they r membrane organelles as a result of infolding of cell membrane

what is the 4 pieces of evidence of endosymbiotic hypothesis/theory?

1. they are the same size as free-living aerobic and phostosynthetic bacteria. (like some prokayotes)

2. they have their own DNA that are not packaged on histones (type of protein found in chromosomes that bind to DNA). the DNA is the shape of a circle. this is all like prokaryotes.

3. self-replicating, divide by binary fission.

4. 2 membranes- outer like eukaryotes, inner like prokaryotes.

(endo=in, symbiosis=living together)

what is mutualism?

good for both organisms in the relatioship

what is commensalism?

good for one organism, other has no impact from the relationship.

what is parisitism

good for one organism, harms the other.

animal cells v.s plant cell:

plant cell: has cell wall, has one large vacuole that contains water and nutrients for the plant to do photosynthesis, they have chloroplasts AND mitochondria.

animal cell: no cell wall, multiple smaller vacuoles, only mitochondria.

main similaritiy: all cells do cellular respiration!

what is cellular respiration?

how cells use sugar and oxygen to create energy, producing carbon dioxide and water as byproducts. this occurs in the mitochondria.

nearly all organelles in a eukaryotic cells are surrounded by a membrane with embedded proteins, many of which are…

enzymes. these make products specifically to that organelle, but their actions benefit the whole system.

the fossil record, which is based on the remains of ancient life, suggests that the first cells were eukaryotic or prokaryotic?

it suggests that the first cells were prokaryotic. therefore, scientists believe that eukaryotic cells evolved from prokaryotic cells in stages.

what is an endomembrane system?

a network of interconnected membranes within a eukaryotic cell that work together to modify, package, and transport proteins and lipids throughout the cell. this includes the ER, golgi apparatus, lysosomes, and the nucleus.

in eukaryotic cells, the nucleus communicates with _______ in cytoplasm

ribosomes

organelles of the endomembrane system communicate with _________

each other

energy-related organelles contain their own ____ and are _________

DNA; self-sufficient

cytoskeletal lattice of proteins fibers that maintains _____ of cell and assists in organelle _________

shape; movement

in eukaryotic cells, what does the nucleus (control center) contain?

chromatin, nucleolus, nuclear envelope.

in eukaryotic cells, what is chromatin?

threadlike material that forms into chromosomes for cell division, contains DNA, proteins, some RNA. inner nucleus stuff around the nucleolus.

in eukaryotic cells, what is the nucleolus?

inner main sphere part of nucleus, forms ribosomes

in eukaryotic cells, what is the nuclear envelope?

double membrane that contains nuclear pores to permit passage of substances in and out of the nucleus

what are the 2 types of ribosomes?

free ribosomes- synthesize proteins that are used within the cell.

bound ribosomes- attached to the outside of the rough ER and make proteins destined for export. (that’s why rough ER is rough)

once proteins are built, they can move to the interior-

through the rough ER and into the smooth ER.

ribosomes have 2 subunits:

one large, the other small. they are composed of rRNA (ribosomal RNA) and proteins.

ribosomes are found in all life forms, reflecting the…

common ancestry of all known life and acting as evidence for evolution.

GSN definition of endomembrane system

GSN/simpler def- a series of intracellular membranes that compartmentalize the cell

what is the endoplasmic reticulum? (ER)

a system of membrane channels connected with the nuclear envelope. it provides mechanical support, carries out protein synthesis on membrane-bound ribosomes, and plays a role in intracellular transport

rough ER functions-

proteins enter the ER for packaging and are then sent to the golgi.

smooth ER funtions-

continuous with the rough ER and forms lipids, metabolizes carbs, and detoxifies drugs and poisons.

protien synthesis occurs __ the ribosomes, some of which happen to be on the ___.

on; ER

what is the golgi apparatus for the cell?

the postal system.

how does the golgi have polarity?

a cis side (facing the nucleus) and a trans side (facing away)

what does the golgi receive from the ER?

receives protein/lipid vesicles(small sacs that move substances in and out of cells) from the ER

describe the system of the golgi apparatus:

molecules leave the smooth ER, enter the golgi from the cis face for modification and packaging, and release them out of the cell (a vesicle can carry the contents to the cell membrane and release them out of the cell).

golgi functions:

-the correct folding and chemical modification of newly synthesized proteins and packaging for protein trafficking

-active in synthesis, modification, sorting and secretion of cell products (trans side)

what are lysosomes?

-the movable stomach of the cell that hydrolyzes macromolecules

-recycles cell’s organic materials

how do lysosomes commit apoptosis?

they can release digestive enzymes that can digest the cell itself if the cell is damaged

lysosomes contain ______ enzymes that can _________ substances the cell has engulfed

hydrolytic; break down

where did the directions of making hydrolytic enzymes for lysosomes come from?

it came from the nucleus, came out on the mRNA, got translated on the ribosomes, and were sent through the ER and the Golgi apparatus, where it “buds off” on the end

lysosomes ______ nutrients from the vesicle, then ___________ on the side of the cell.

digests; discharges waste. example: white blood cells and bacteria.