Cell Structure, Function, and Energy Processes in Biology

what is a cell

cell is the smallest functional and structural unit capable of carrying out the life processes

what do functional activities of each cell depend on

specific structural properties of the cell

are cells living building blocks of all plant and animal organisms

yes

what do all new cells and new life arise from

preexisting cells

3 componets of a cell

plasma membrane, nucleus, cytoplasm

the plasma membrane bound in the cell is composed of what?

selectively permeable and made of phospholipids

nucleus

contains genetic material (DNA in chromosomes)

Transcription

simply copying a recipe from your DNA's master cookbook into a portable note called mRNA.

translation

is actually cooking the meal; your cell's machinery (ribosomes) reads the mRNA note and builds a functional protein

cytoplasm

portion of the cell outside of the nucleus but contained by plasma membrane, contains organelles and cytosol

what is the other name for the plasma membrane

cell membrane

things the plasma membrane does

surrounds every cell, seperates cell contents (ICF+ECF), controls movement into and out of cell, made of phosolipids

nucleus

enclosed by a double layered nuclear envelope, contains cell's genetic material, DNA, serves as a genetic blueprint during cell replication, directs protein synthesis

cytoplasm

portion of the cell interior not occupied by the nucleus, consists of organelles (little organs), cytosol (complex, gel-like mass in which the cytoskeleton is found)

transcription

taking the DNA into a language the cell can now read

Translation

taking RNA into proteins

examples of organelles

endoplasmic reticulum (ER), free ribosomes, Golgi complex, mitochondrion

endoplasmic reticulum

smooth er, rough er, network that is inside the cell, elaborate fluid filled organelle with lots of membranes distributed throughout the cytosol

Er is also known as the

packaging center

rough ER

surface has ribosomes attached and involved in protein synthesis, most abundent in cells which specialize in protein secretion

Smooth ER

no ribosomes attached, not involved in protein synthesis, helps form transport vesicles, lipid synthesis, detoxification in liver through the smooth ER

vesicle

sphere of phosolipids

transport vesicle

sphere of plasma membrane that moves across the cell that has protein within the cell

secretitory vesicle

a vesicle that will go to the plasma membrane, release the protein into an environment outside of the cell

what does lipid synthesis do

processes cholesterol which makes steroid hormones

why does a rough ER look rough

because of the dots (ribosomes) can assume protien is being made

ribosomes

can be attached to ER but can also be floating either way always making proteins

Golgi complex is known as

the distribution center

funtions of the golgi complex

modifies the proteins secreted by the Er and prepares them for distribution, sorts and directs finsihed products to their final destination

what is the goli complex closely associated with

the ER, which consists of a stack of flattened, curved membrane enclosed sacs called cisternae

what is exocytosis

process that allows the cell to secrete its products

are there ribosomes on the golgi complex

no

desribe excoytosis

the rough er makes proteins puts it into vesicles, then sent to golgi apparatus and gets a label on where to go into a vesicle then it gets released

mitochondria

it makes ATP, energy organelle, contains enqymes for citric acid cycle (krebs cycle) and electron transport chain, enclosed by a double membrane

what is the double membrane enclosed by called

cristae

protein life span

1. bulding blocks the dna strand in nucleus

then receiving division what happens

the DNA is translated into RNA in nucleus which is a language ribosomes can read

next is processing divison which means

ribosomes can translate the RNA into protein

next is packaging divison

protein is packaged into a vesicle in the ER

next is distribution which means

golgi modifies the protien if needed and directs its path to a cell

next it arrives at the cell location or secreted and does it funtion which means it

enables the cell function and secretion

what does celluar energy =

ATP

energy in the cell is used to what

do mechanical things, transport things around the cell and across cell membrane, build things in the cell

what are energy sources

carbohydrates, lipids, protein

anabolic reactions use

energy to build things, and require energy

catabolic reactions breaks

things down those storage molecules and release enery

making ATP

you breakdown molecules and release energy (catabolic reaction) which is converted to ATP which is later used to build new bonds (anabolic reaction)

3 main processes in making ATP

Glycolysis, krebs cycle, electron transport chain

Glycolysis

takes glucose and breaks it down into acids happens in the cytoplasm and aerobically (does not require O2) not a lot of ATP at least 2

Krebs Cycle and electron transport chain require what

(require O2) and are aerobic processes

Electron Transport Chain (ETC)

by products of the krebs cycle and create a bunch of ATP like 3 or 4

what is the requirment for mitochondria to be involved in making ATP

O2

Krebs Cycle

aerobic process, net 2 ATPS from each 3 carbon molecule

what is the lipid bilayer that makes up the plasmic membrane

extremely thin layer of lipids and proteins that forms outer boundary of every cell, and genuinely hydrophobic and hydrophobic

hydophillic

face the inside and outside of cell where water is

hydrophobic

do not like the water so go to the middle of the lipid bilayer

what else does the lipid bilayer do

mechanical barrier to hold the contents of the cell, participates in joining cells to form tissues and organs, plays a role in the ability of a cell to respond to changes of the cell environment

what is the fluid mosaic model

it refers to "fluid" movement of the lipid membrane plus the addition of a protein "mosaic"

where is the cholesterol located in the plasma membrane structure

between phosolipid molecules and contributes to the stability of the cell membrane

what else does the plasma membrane constain

carbohydrates on outer surface only to bound to membrane proteins

membrane proteins are

are attached or inserted within the lipid bilayer and has 6 major functions

what are the 6 major functions of the membrane proteins

channels, carrier problems, docking problems, receptors, call adhesion molecules (CAMS), glycoproteins

where are intergral proteins located

firmly inserted into and extend across the lipid bilayer and go across entire cell membrane

where are peripheral proteins located

loosely lie on the inner and outer surface of the cell membrane

what are channels

intergral proteins and across entire membrane and create a tunnel and allow passage of small things, may be opened or closed and depends on weather there charged

what does a charged molecule mean

it means its hydrophilic and like water which will create a channel to get through

carrier proteins

intergral proteins and across the membrane, involved with carrier mediated transport, specific for larger molecules, carries large molecules

docking proteins

located on the inner surface and where secretory vesicles bind prior to exocytosis

receptos

it binds with specific molecules in the cells environment, specific cells have specific receptors

CAMS

connect cells together and bind tightly side by side each other to hold tissue together, proteins that stick outside cell

glycoprotein

sugar and a protein stuck together, usually peripheral proteins, proteins attached to carbohydrate-usually used for a cell recognition, recognition of target cells

what happens when membrane proteins do not work

autoimmune disorder happen (cystic fibrosis) a channel will not let epithelial tissue go through so it clogs and makes mucus in the lungs

what can genetic defects cause

genetic defects causes a defective protein which means the structure is messed up up and everything else will be messed up

cell to cell adhesions

bind groups of cells into tissues and package them into organsm once arranged they all head together

what are cell to cell adhesions binded together by

extracellular matrix (biological glue), CAMS in cells plasma membranes, specialized cell juntions

what are the types of cell junctions

tight junctions, and gap junctions

tight juntions hold

the cell together and create a seal

gap juntions are

a hole between 2 cells and help the cell communicate

tight junctions functions

bond adjacent cells tg, seal off the passageway between 2 cells, and prevent undesirable leaks within the epithelial sheets

tight junctions are found in

sheets of ephithlial tissue

gap junction functions

small connecting tunnels form by connexons, abundant in particular cells that want to transport electricity (ex: muscles)

in non muscle tissue what do gap junctions permit

unrestricted passage of small nutrient molecules

what forces are associated with transport

active and passive transport

what determines if the cell can cross the membrane

its size and its solubility, and weather its charged (uncharged and non-polar does not like water can go through lipid membrane)

what molecule that is nonpolar can still pass through membranes

H2O

is the cell membrane selectively permeable

yes

what does permeable mean

substance can cross membrane

what does impermeable mean

substance can not cross membrane

passive transport

does not require energy (ATP)

active transport

requires energy (ATP)

what is diffusion

passive movement of molecules move from area of high concentration to area of low concentration

is diffusion crucial to survive every cell

yes

what does diffusion play an important role in

substance entering and leaving the cell, exchange of O2 and CO2 between blood and air in lungs, movement of substances across kidney tubules

eventually what is produced after diffusion

equilibrium

ficks law of diffusion

1. Magnitude, 2. Permeability, 3. surface area of the membrane, 4. molecular weight, 5. distance

osmosis

passive diffusion of water, net diffusion of water down its own concentration gradient (water moves towards solute)

when is osmosis significant

when solutions are infused into our blood

what solution = our cells and tissues and if not used correctly what can happen

0.9% NaCl if not thus our cells can lose water or gain water and swel

isotonic solution

has the same concentration of non-penetrating solutes as normal body cells

hypotonic solution

has a lower concentration of non-penetrating solutes than normal body cells