Bio 181 module 3

so far lecture 7 8 9

phospholipids

• the major type of lipid found in the cell membrane

• hydrophobic and hydrophilic parts

hydrophilic

polar head group

hydrophobic

• fatty acid chains

• glycerol backbone

structures

• phospholipid bilayer

• membrane

• inner environment

• outer environment

diffusion

• net movement of solute from an area of higher solute concentration to the area of lower concentration

• a passive process that can occur in water, air, ect

• influenced by temp and density

osmosis

passive process by which molecules of a solid tend to pass through a semipermeable membrane from a less concentrated solution into a more concentrated one, creating an equalizing concentration on each side of the membrane

hypertonic

concentrated on inside membrane

isotonic

equal concentration both sides membrane

hypertonic

concentrated on outside of membrane

Cell theory

all living organisms are made of cell

cell theory #1

all organisms are composed of one or more cells

cell theory #2

the cell is the basic unit of structure and organization in organisms

Prokaryotic cells (pro = before; kary = nucleus)

do not contain any internal membrane- bound organelles and are generally single celled

Cell envelope ( prokaryotic architectural region)

generally a plasma membrane covered by a cell wall

cytoplasmic region (prokaryotic architectural region)

containing the genome (DNA), ribosomes, and proteins

Plasmids

in prokaryotes where they carry extra chromosomal DNA

flagella / pilli 9prokaryotic architectural region)

can project from the cell surface/ reproduce

nucleoid region

where prokaryotic chromosomes (DNA) is in the cells central part

cytoplasm

gelatinous liquid that contains part of the cell (H2O, salts )

Ribosome

facilitate protein synthesis

cell membrane

selectively permeable membrane that allows some molecules in, made of liquids

cell wall

provides structure and usually made of peptidoglycan

capsule

outermost layer of carbs, allows cell to be sticky

Fimbriae (AKA pili)

helps cell attach to other surfaces

gram- positive

bacteria have thick cell walls made of peptidoglycan and stain purple

gram- negative

bacteria have thin peptidoglycan layers and an outer membrane, stain pink or red

Eukaryotic cells

contain membrane-bound nucleus and organelles

Eukaryotic cells types

• animal

• plant

• fungus

• protist

nuclear envelope

membrane enclosing nucleus

chromatin

DNA plus associated

nucleolus

condensed region where ribosomes form

peroxisomes

metabolize waste

rough ER

makes secretory and membrane proteins

smooth ER

makes lipids

vacuole

store and transport materials

microtubules

form mitotic spindle

centrosome

microtubule organizing center

intermediate filaments

proteins that hold organelles in place

microfilaments

form cellular context

plasma membrane

phospholipid bilayer

lysosomes

digests contents

golgi apparatus

modifies proteins

cytoplasma

jelly like substance that contains organelles

plant cell cell walls

maintains cell shape

plant cell chloroplasts

site of photosynthesis

plant cell plasmodesmata

channels that connect 2 plant cells

plant cell plastids

pigments

The Cell membrane structure

• a plasma membrane that surrounds the cytoplasma of the cell

• a phopholipid bilayer with embedded proteins that seperates the internal contents of the cell from its surrounding environment

• controls passage of the organic molecules, ions, water and oxygen in / out

The cytoplasm structure

• cells entire region between the plasma membrane and the nuclear envelope

• comprised of organelles suspended in the gel-like cytosol, the cytoskeleton, and various chemicals

the nucleus structure

houses the cell’s DNA and directs synthesis of ribosomes and proteins

nuclear envelope structure

double-membrane structure that constitutes the nucleus’ outermost portion, allows material to move in/out

nucleoplasm structure

semi-solid fluid inside the nucleus where we find the chromatin and nucleolus

nucleolus structure

allows for assembly of protein ribosomes

chromosome structure

structures within the nucleus that are made up of DNA

chromatin structure

unwound protein-chromosome complexes and makes up the chromosomes both when condensed and decondensed

ribosome structure

• cellular structures responsible for protein synthesis

• may be attached to plasma membranes cytoplasmic side of the ER’s cytoplasmic side and nuclear envelope’s outer membrane

Endoplasmic reticulum (ER) structure

• membrane bound organelle in eukaryotic cells

• involved in protein and lipid synthesis

• packages and scretes many of the products made by a cell

Rough ER structure

synthesizes and stores proteins

Smooth ER structure

Production and metabolizes fats and steroid hormones

golgi apparatus structure

• transports, modifies, and packages newly made proteins and lipids in eukaryotic cells

• made of flattened, stacked pouches called cisternae

mitochondria sturcture

• provide energy to eukaryotic cell by converting sugars into atp

• has outer membrane and inner membrane

mitochondria inner membrane structure

folded into invaginators called cistae (where aerobic respiration takes place)

peroxisomes structure

• small and round organelles enclosed by a single membrane

• carry out oxidation reactions that break down fatty and amino acids

vesticles and vacuoles structure

• membrane-bound sacs that function in storage and transport

• can be in animal and plant cells

• vesicle membranes can fuse with either the plasma membrane or other membrane systems in the cell

cell division is the process by which cells make more cells

• vital for propagation

• normally under tight regulation

• can look different for different types of cells

The dna of eukaryotic cells is organized as chromosomes

• humans have 46 arranged into 23 pairs

• other organisms have other #’s

Karyotype is portrait of the human chromosome

• can be identified by its appearance in the microscope

• humans have 23 pairs in our somatic cells ( 1 from m and d)

Ploidy

the number of complete sets of chromosomes in a cell

haploid

cell w/ one complete set

diploid

cell w/ two complete sets

polypoid

cell w four or more sets

sister chromatids

two identical copies of the chromosome

Genome

a cell’s DNA packaged as a doubled stranded DNA molecule

Prokaryotic genome

composed of a singular double stranded DNA molecule

upon fertilization

each gamete contributes one set of chromosomes

genes

the functional units of chromosomes, determines characteristics by coding specific proteins

homologous chromosomes

a diploid cell containing matched pairs of chromosomes

first lvl of compaction

short stretches of the DNA double helix wrap around a core of histone of proteins

chromatin

DNA- histone complex

Nucleosome

beadlike, histone DNA complex

linker DNA

DNA connecting the nucleosomes

binary fission in prokaryotic cells

• single origin of reproduction where the circular chromosome begins replication bidirectionally

• Ftsz gene plays a central part in prokaryotic cell division

• as division proceeds the cell elongated before splitting off into two daughter cells

cell cycle

• describes the life cycle of a prokaryotic cell and produces two daughter cells at the end

• has m phases (actual division) and interphases (cell’s prep for division

interphase

the nucleolus and the nuclear envelope are distinct and the chromosomes are in the form of threadlike chromatin

G1 phase (Interphase)

• the cell is accumulating building blocks of DNA, associated proteins, and energy reserves

• cell growth and normal functions

S phase (interphases)

• the DNA is copied

• chromosome # starts at 46

• chromatid doubles to become 92

G2 phase (interphase)

• cell replenishes energy stores

• some organelles are duplicated

• cytoskeleton is dismantled

• additional growth (chromatids become replicated chromosomes)

Prophase ( mitosis)

the chromosomes appear condensed

prophase (mitosis) stages

• chromosome become visible

• mitotic spindle is assembled in the cytosol

• microtubules assemble off the cytostome - to prepare to eventually separate the sister chromatids

Prometaphase (mitosis)

• still prophase

• chromosomes continue to condense and are more visible

• centrosomes continue to move towards opposite poles

Metaphase (mitosis)

• thick coiled chromosomes are lined up in the center of the cell on the membrane plates, spindle fibers are attached to the chromosomes

metaphase (mitosis) stages

• the mitotic plate is fully developed and centrosomes are at opposite poles

• chromosomes are aligned at the “equatorial plate” and each sister chromatid rests on one side of the plate

Anaphase (mitosis)

the chromosomes have separated and are moving toward the poles

anaphase ( mitosis) stages

• sister chromatids are pulled apart by the spindle fibers and separated from each other]

• each chromatid is now a chromosome

Telophase (mitosis)

The chromosomes are at the the poles and are becoming more disuse, the nuclear envelope is now reforming, and the cytoplasm may be diffusing

telophase (mitosis) stages

• chromosomes arrive at opposite poles and start to decondense

• nuclear envelope reassembles and begins to surround each new chromosome

• the mitotic spindle assembly breaks down and the division of the cytoplasm begins via cytokinesis

Cytokinesis (mitosis)

during which cell division is completed via the physical separation of the cytoplasmic components into 2 daughter cells

G0 phase (mitosis)

cells aren’t actively preparing to divide and are in an active stage of the cell cycle

meiosis

• a form of cell division that includes 2 rounds of nuclear division

• the number of chromosomes are cut in half from the normally diploid somatic cells yield the haploid gamete

• “crossing-over” where genetic material is exchanged between the paternal and maternal bonding

2 goals of meiosis

1. create gametes (sperm and eggs)

2. randomly jumble up the chromosomes so that each gamete