isci ch 15.2

what are cells

the smallest unit of life

types of cells

-unicellular

-multicellular: several cells of one kind interconnect with each other

how are tissues and organs formed

-cells perform shared functions to form tissues

-several tissues combine to make an organ

-organs combine to make an organ system

TWO CATEGORIES OF CELLS

-prokaryotic

-eukaryotic

what is a prokaryote

no nucleus or membrane bound organelles

-bacteria

-archaea

what is a eukaryote

has nucleus and membrane bound organelles

-animal

-plant

-fungi

-protists

who is Anton van leeuwenhoek

-observed bacteria and movement of protist/sperm

-called them animalcules

who is Robert Hooke

-coined the term "cell"

-looked at thin pieces of cork; cellulae

what was the common idea in the 1830s

all plants and animals are made of cells!

what did schlep and Schwann do

developed the cell theory; all living things are composed of cells& cells come from other preexisting cells

where did the fist cell come from

3.5 BYA⭐️⭐️⭐️⭐️

-free floating molecule

-most likely prokaryotic

how old is earth

4.6 billion years old

WHAT ARE PROPERTIES OF ALL CELLS

1. bound my plasma membrane
2. have chromosome(s) carrying genes made of DNA
3. contains ribosomes used to make proteins
4. cytoplasm refers to the jelly like inside of the cell
5. two types: prokaryote and eukaryote

what is the cytoplasm

between the pm and the nuclear membrane

-made up of organelles suspended in the gel like CYTOSOL

-70%-80% water

plasma membrane

-every cell is enclosed in a plasma membrane

-phospholipids are not locked into place in membrane: float around on their side as a bilayer; other components not anchored as well, hydrophobic tails and hydrophyllic heads

-phospholipids help prevent leaking and forms boundary

types of proteins in the pm

-transmembrane: penetrates the entire lipid bilayer

-surface proteins: resides primarily in the inner or outer surface of the membranes; ALWAYS HYDROPHYLLIC

diffusion

-passive transport in which solute is dissolved in solvent

-moves from high concentration to low ("move down their concentration gradient")

types of diffusion

-simple: small uncharged molecules (o2 and co2) can pass directly through pm with ought assistance

-facilitated: needs help from transport proteins

-most molecules cannot get through pm (polar molecules)

what is osmosis

WATER MOLECULES will move from areas of high concentration

-equalized water inside and outside of cell

-diffusion of water across membrane is osmosis

what limits water flow

hydrophobic region

-aquaphorins in the bilayer help water transport

WHAT IS TONICITY

relationship between solutes concentration inside and outside the cell

DIRECTIONS OF OSMOSIS

-isotonic: perfectly balances

-hypotonic: solute concentration is higher in the cell (plants love)

-hypertonic: solute lower in the cell (pickles)

prokaryotic structural features

-pm

-cytoplasm

-ribosomes

-DNA in nucleotide region (circular in bacteria)

WHAT ARE BACTERIA CELL WALLS MADE OF

PEPTIDIOGLYCAN

what does the bac cell wall do

-protect and prevent dehydration

-gram pos (thick) and gram neg (thin)

-can serve as a target for antibiotics

eukaryotic cells

-appeared on earth 2 BYA

-not all are multi-cellular

-10x the size of prok by volume

eukaryotic tour

-nucleus: linear DNA

-organelles: specialized structures with specialized functions in cytoplasm

eukaryotic cell functions

-manufaturing

-breakdown

-energy process

-structural support

what organelles is specific to animal cells

centriole

what organelles are specific to plant cells

-cell wall

-vacuole

-chloroplasts

nucleus

-nucleolous: ribosomes assembly

-chromatin: DNA

-nuclear membrane: 2 bilayers

chromatic/ chromasomes

-chromatin: long thin fibers consisting of DNA and proteins

-chromosomes: when cells divide chromatin colds and becomes chromosomes

er

-rough or smooth

-proteins and lipids are produced in compartments of the er

-molecules packaged here

rough er

-connected to nuclear envelope

-PRIMARY FUNC IS TO FOLD AND PACKACGE PROTEINS

-also makes more membrane

-ribo attached to the er make proteins used in membranes

ribosomes

-carry out protein synthesis

-found free in cytoplasm and bound to rough er or outside nuclear envelope

-comprised of large or small subunit

-MADE IN NUCLEOLOUS

smooth er

-part of the end-membrane system (no ribs)

-functions: synthesizes lipid and detoxifies alcohol and drugs

Golgi apparatus

-part of the end-membrane system

-where the cell processes products for delivery throughout the body (proteins)

lysosomes

-round meme enclosed, acid filled vessels

-WATSE DISPOSAL

mitochondria

-ALL PURPOSE ENERGY CONVERTERS

-ATP!!!!!

centriole

-animal cell only

-used for cell division

cell wall

-plant only

-made of CELLULOSE

-archaea bac and fungi all have cell walls

-funtions: protection, water retention, strength

what is bacteria cell wall made of

PEPTIDOGLYGAN

what is fungi cell wall made of

CHITIN

vacuole

-stores water in plant cells

-50%-90% of cell interior space

-OSMOSIS!!!!!

-TURGOR PRESSURE!!!! wilting and blooming

chloroplast

-light energy to chem energy

-2 distinct layers of membrane (like mitochondria)

-parts: stoma, thylakoids and granum