Lecture Module 1 | Cells: The Living Units (Ch 2)

fast metabolism

cells burn through/use energy quickly

slow metabolism

cells burn through/use energy quickly

cells

smallest living units in our bodies

organelles

‘little organs’

carry on essential functions of cells

enzymes

proteins that direct chemical reactions in cells

metabolism

the sum of all chemical reactions in the cell

enzymes

proteins that direct chemical reactions in cells

metabolism

the sum of all chemical reactions in cells

cytoplasm

all organelles + liquid

nucelus

control center of cell

plasma membrane/plasmalemma

outer boundary

separate EC + IC compartment of cell

What is the purpose of the plasma membrane?

The majority in/outside of a cell is…

water

flexible layer that defines extent of the cell

plasma membrane

phospholipid composition

2 FA

phosphate group

polar hydrophilic head

hydrophobic tails

phospholipids form a 2-layered membrane the

phospholipid bilayer

The nature of the phospholipid bilayer is always

Hydrophobic

All biological membranes are…

Hydrophobic

What is embedded in the phospholipid bilayer?

Proteins… like a mosaic

Molecules can… in the membrane

move freely

Membrane is fluid/rigid

Fluid

What makes one cell different from the other?

Different kinds of protein composition and cell surface

What is integral membrane protein?

transmembrane

span entire membrane (both hydrophilic & hydrophobic)

What is used for cell signaling, WBC?

Peripheral membrane protein,

destroys foreign bodies

What is a peripheral membrane protein?

Unilateral, one side of the protein

Used for cell signaling

How can WBCs recognize your cell vs. foreign cells?

Cells contain different kinds of proteins/markers that indicate cell-cell recognition not to destroy

What percent of glycolipids make up of the PM?

10%

What percent of the plasma membrane is carbohydrates?

5-20%

lipid

sugar with fat attached

epinephrine is hydrophilic

cannot flow through membrae

How does epinephrine (adrenaline), hydrophilic travel through PM?

It must bind to a receptor protein because it is water loving.

Pass message → inside

Protein receives that message → keeps going until signal receives final destination in the cell

Plasma membrane controls…

what comes inside and outside of the cell

diffusion of water from high to low concentration

diffusion

cell eating

phagocytosis

pinocytosis

cell drilling

What is receptor mediated endocytosis

plasma proteins bind to x molecules; membranes invaginate and form a coated pit, and pinch off → become a coated vesicles

What lies internal to plasma membrane; consist of cytosol & organelles

cytoplasm

Cytosol

jelly-like fluid where cellular elements are supsended

water, ions + enzymes

What is the purpose of ribosomes?

site of protein synthesis

free ribosomes

function inside the cytosol

bound ribosomes

export or membrane bound

Rough ER

Role in protein syntehsis, does not produce proteins, but has a role in making emmebrane proteins

Smooth ER

cell metabolism role

does not make proteins, no ribosomes

Golgi apparatus

packing + shipping center

3-10 disk-shaped membrane bound envelopes

Sorts products of rough ER at the ‘cis’ end and sends them to proper destination from the →

trans end, GA

Nothing goes anywhere in cell without moving through…

Golgi apparatus

Mitochondria

generates the majority of cell’s ATP (energy by cellular response)

power plant

Mitochondria is enclosed by…

double membrane

inner membrane folds in forming shelf-like cristae → has own DNA

lysosomes, peroxisomes, vesicles are all

membrane-bound sacs

spherical membranous bags contain digestive enzymes

lysosomes

digest ingested bacteria, viruses, toxins + degrade nonfunctional organelles

breakdown glycogen + release thyroid, breakdown non-useful tissue

lysosomes

secretory lysosomes

found in WBC, immune cells, melanocytes

peroxisomes

membranous sacs counting oxidases + catalases

free radicals

lacks electrons

mutation

change to DNA

elaborate network of rods

supports cellular structures + provides machinery for various cellular movements

cytoskeleton

microtubule

cyldrincal structure made of tubulin

microtubules radiate from

centrosome

microfilament composition

actin

actin filaments composition

contractile protein that interact with/ myosin → produce force

help w/ cell division, endo/exocytosis

organelles attach to and move along actin filaments

thinnest filament

actin

intermediate filaments

protein fibers most stable, permanent

provide tensile strength

play a role in linking cels together

centrosome

a spherical structure in the cytoplasm

centrosome composition

centrosome matrix and centrioles → microtubules are anchored at the centrosome microtubule organizing center)

centrioles

paired cylindrical bodies forming pinwheel array of nine ripples of microtubules

secretory lysosome

found in WBC, immune cells, melanocytes

nuclear envelope

two parallel membranes separated by fluid-filled space

chromatin

composed of DNa + histone proteins

condensed chromatin

(inactive)

tightly coiled strands of DNA

extended chromatin

has uncoiled strands of DNA, when DNA’s genetic code is copied → mRNA

transcription

the highest level of organization of chromatin

chromsomes

nucleotides

sugar + phosphate + base

building block for NA

nucleolus

center of nucleus

has parts of several chromosomes

site of ribosome subunit manufacture

makes rRNA

cell cycle

series of changes a cell goes through; 2 major parts

Part 1 = interphase

g1, first part of interphase

S phase

DNA replicates t o ensure daughter cells get identical copies of genetical material

G2 phase

growth 2 phase, during S and G2 phase cells resume normal activities

part 2 = M (mitotic) phase

cell divide during this stage; follows interphase

cytokinesis starts when..

late anaphase, apart of mitosis

Prophase

Chromatin condense into chromosomes attached to one another by a centromere

Nuclear envelope disappears

Centriole pairs separate + Mts begin o att → centromeres, move sister chromatids to center

sister chromatids cluster at

arrangement of Chs. along plane midway between poles is the…

middle of cell with centromeres aligned at center

metaphase plate

centromeres of the sister chromatids

split +each becomes a Ch again

motor proteins Chs toward poles

telophase + cytokinesis

new nuclear membrane is reformed

new set of chromosomes extend into chromatin

cytokinesis complets CD → cleavage furrow

→ formed in late anaphase + cytoplasm pinched two two parts after mitosis

your body has 200 different..

cell types

fibroblast

makes and secretes protein component of fibers

erythrocyte

concave shape provides surface area for uptake of respiratory gases

epithelial cell

hexagonal shape allows

skeletal and smooth muscle cells

elongated and filled with actin + myosin; contract forcefully

fat cell (adipocyte)

shape is produced by large fat droplet in its cytoplasm

macrophage (fights disease)

phagocyte that moves thru tissue → reach infection sites

neuron

has long processes for receiving + transmitting messages

oocyte (female)

largest cell in the body

sperm (male)

posses long tail for swimming to the egg for fertilization

free radical theory

damage from byproducts of cellular metabolism

radicals accumulate, damage essential cell molecules

mitochondrial theory

a decrease in production of energy by mitochondria weakens and ages our cells

genetic theory

proposes that aging is programmed by genes

telomeres

prevent telomeres from degradation