Anatomy & Physiology - Ch. 3, Cells

an adult human body has about _____ cells

70 trillion

why does cell count fluctuate?

cells are continuously being born, and always dying as well

** HOMEOSTASIS!!!

differentiation

cell develops to gain specialized function

how many cell types?

at least 260

what are cells measured in?

micrometers (10^-6)

the egg, red blood, and smooth muscle cells all are _____ in size and have __________ that allow their functions to work

• small

• distinctive shapes (NOT all bubble shaped)

changing cell shape alters its ability to…

function

a typical cell (does or doesn’t) exist? Explain.

DOESN’T

• size, shape, structure all vary

all cells share ___ main parts

4

• MUST be present

which cell’s 4 main parts that MUST be present?

• cell membrane

• cytoplasm

• nucleus

• inclusions

Inclusions

cell HAS to have chemicals

• different chemicals for different cells

• the name tells where the chemicals are at

  • chemicals in cell for this one

Chemical Composition of the Body: Water

64%

Chemical Composition of the Body: Proteins

16%

Chemical Composition of the Body: Fats

16%

Chemical Composition of the Body: Minerals

4%

Chemical Composition of the Body: Carbohydrates

1%

Chemical Composition of the Body: Vitamins

less than 1%

Nutrients

collective term for chemicals/molecules your body needs to break things up, rebuild, & break apart again

• cycle continues until death

• make up doesn’t = perfect 100% bc estimates

  ** HOMEOSTASIS in chemical level

  ** Assimilation

Water

how we move chemicals everywhere

• gets stuff where it needs to go

Carbohydrates

• long units of simple sugars (glucose)

• major source of ATP

• quick energy (sugar rush)

Carbohydrate Shape?

hexagons and pentagons

Fats

• long carbon chains called “fatty acids”

  • usually 3 long chains

• used as a storage of energy, making structures and steroids

  • slow, long term energy

anything ESSENTIAL means that it must be ______ to be in your body

ingested

carbohydrate picture/shape?

fat picture/shape?

what is the first ‘box’ called in this picture?

glycerol

glycerol?

back bone of fat

proteins

makes up many structures and chemicals of the body (do ‘everything’)

• most complex chemical structures

• brings N into the body (not much needed)

• made of Amino acids (contain N) that are linked by peptide bonds

  • 20 total, 9 essential (must be ingested)

Minerals

• inorganic (metals → + charged)

• vitamins: A, B, C, D, E, K

  • promote actions of minerals

• Ions: Ca²+, Na+, K+, Fe²+

organic

carbon-based (O, H)

Cell Membrane (a lot to it)

• what does it do?

• properties?

protects, absorb, secrete, excretes

• surface membrane that separates the external environment from the internal environment (ECF vs. ICF)

  • actively functioning part of the living material

• extremely thin, but flexible

  ** controls entrance & exit of substances → most IMPORTANT function

  • selectively (semi) permeable = certain things go in or out

• just follows orders, doesn’t think

cell membrane: Signal Transduction

allows cells to to receive and respond to incoming messages

• link to cells and the BODY’s internal environment (ECF)

Cell Membrane Composition

• fluid mosaic model (little pieces make big picture)

• some carbohydrates, cholesterols, glycolipids (signal transductions)

• lipids > proteins

  • 50 lipids per 1 protein

**most importantly made up of phospholipids and proteins

Cell membrane composition: Phospholipids

lipids that contain phosphorus (PO4³^-)

Phospholipids: ‘Heads’

water-soluble phosphate group from the outer surface (hydrophilic)

• always on the outside bc they like water

• polar: have charge → want to react

Phospholipids: ‘Tails’

water-INsoluble fatty acid chains that make up the interior of the membrane (hydrophobic)

• nonpolar: no charge → don’t want to react

  ** oil (FAT) doesn’t mix with water

Tails: the oil with lipid soluble

• inside is oily

• water soluble = lipid soluble bc of oily nature in the inner membrane (substances pass easily)

  ** membranes only let things in that have compatible chemical structure, not ‘need’ and ‘don’t want’ (water and heroine for example)

  • oxygen, CO2, steroids

Tails: the oil with water soluble

• water soluble molecules do NOT pass easily (tails resist)

• amino acids, sugars, proteins, ions: CHARGED → all have trouble passing through

non-polar also means that it doesn’t react or it is…

stable

the presence of __________ also affects cell membrane permeability

cholesterols

Protein types?

• membrane

• integral

• peripheral

membrane protein

many different types, provide specialized functions

cell membrane sketch

Integral Protein

extends from ECF (outside) to the ICF (inside)

• provide routes into and out of the cell for smaller molecules & ions

• bind to specific molecules (like hormones)

• provide pores for water molecules to enter

  • water: can’t go across phospholipids, but has many more doorways/paths, like this one

  ** BEST door ways bc door goes all the way through

Integral Protein sketch?

Peripheral Protein

does not extend all the way through, remains at surface

• many are enzymes and take part in signal pathways

• act as “cellular adhesion molecules”: allow certain cells to touch or bind

  • makes bigger, better structures

    → cluster to form tissue

    → identify cells as ‘it’s cells’

  ** NOT a good door way, only is one when it need to be one

Peripheral protein sketch?

which protein acts as the best ‘door’? the worst?

Integral, Peripheral

what is the most important molecule that Integral proteins provide a pathway for?

WATER (bc it can’t cross phospholipids)

Aquaporins

door for water

many peripheral proteins are ________ and take part in _____ ____________ pathways

enzymes, transduction pathways

What are the two main functions of the Peripheral protein?

• make bigger structures by cells clustering tgr

• identify cells as ‘it’s own cells’

A?

ECF (outside)

** side where the most stuff is sticking out

B?

Glycolipid

C?

Carbohydrate (sugar)

D?

Glycoprotein

E?

Phospholipid Bilayer

F?

Lipid Tails

G?

Phosphate Heads

H?

Integral Protein (have to see both ends)

I?

Cholesterol

J?

ICF

K?

Peripheral Protein

• can only see part of it → assume it doesn’t go all the way through

Cytoplasm

intracellular fluid environment

what does the cytoplasm contain?

• Cytosol

• Organelles

• Inclusions

**COI

Cytosol

fluid that surrounds organelles & disolves solutes

• cell soln. (break up word)

Organelles

parts of a cell that have specific functions

Cytosol make up

75-90% water

• proteins

• carbs

• lipids

• inorganic substances

why does can’t cytosol have less than 50% water?

it needs water to move stuff

Cytosol traits?

• not very viscous (how syrupy something is, lvl of fluidity)

- means it has a consistency like water

• transparent

cytoskeleton picture/look?

cytoskeleton

series of protein rods & tubules that form a supportive framework

• support framework for cell

some organelles?

• Ribosomes

• ER

• Gogi Complex

• Mitochondria

• Lysosomes

• Peroxisomes

Ribosomes

tiny, ‘dots’ composed of proteins & RNA

• assemble amino acids to form protein chains (amino acids make proteins)

• found in the cytoplasm & on the ER

• make proteins

Ribosome pic/look like?

Endoplasmic Reticulum

ER

• membrane-bound, flattened sacs, elongated canals, & fluid-filled vesicles (vacuole)

• interconnected w/ the cell membrane & other organelles

ER pic/look like?

ER Function?

• bc it is interconnected → communicates (w/ cell membrane & other organelles)

• provides a tubular transport system for molecules throughout the cell

→ good at this bc it’s everywhere

Vacuole

bubble → puts stuff in it to prevent from reacting

vacuole pic/looks like?

2 Types of ER?

• Rough ER

• Smooth ER

Rough ER

contains ribosomes on the surface

• help w/ protein synthesis (makes proteins)

Smooth ER

have no ribosomes

• helps…

  • lipids synthesis

  • fat absorption (in GI tract) → take things & move em through out body

  • breaking down drugs

Gogi Complex (body or apparatus are other names)

• stack of 6+ membranes called cisternae (picture)

What does the Gogi Complex do?

refines, packages, & delivers proteins synthesized by the rough ER

• refines: chemically changed so it can be delivered

• chemically modified glocoprotein as they pass from sac to sac

Golgi Complex look like/pic?

Golgi Complex: Transport Vesicles

chemically modified proteins and lipids are packaged in the golgi membrane to form these

Mitochondria

• cristae

• contains OWN DNA for making a small # of protein & specialized RNA (chemicals)

• filled w/ matrix

• typical cell contains 1,700 mito.

Cristae

double-layer membrane, inner layer forms folds

• (+) surface area where chemical rxns can occur

Matrix

mitochondria filled w/ enzyme-solution fluid

Mitochondria function?

• can divide

• makes some proteins & RNA (chemicals)

• release energy from glucose & organic nutrients forming…ATP → eat to get energy

Mitochondria pic/look like?

Lysosomes

destroy

• contain enzymes to dismantle debris (proteins, carbs, nucleic acids, bacteria, old worn cell parts)

  • contains more than 40 diff enzymes

• only function under acidic conditions so they do not destroy the cells around them (bc kills all organic matter)

  • ph helps control

  • no one knows how they don’t kill themselves

Lysosomes pic/look like?

Peroxisomes

• present in all cells, but much more abundant in liver and kidney cells

• contains enzymes (peroxidases) → biochem rxns

Peroxisomes pic/look like?

• also bubble bc more specific lysosome

• Peroxisomes function?

• catalyze (accelerate) metabolic rxns to release H2O2 (which is toxic)

→ then uses enzymes (catalase) to destroy H2O2 (breaks down H2O2 → H2 and O2) to make it NOT toxic

• helps form bile salts → digest fats

• breakdown large lipid chains and rare biochemicals (acid-based)

• detoxification of alcohols

Centrosome

• located near the nucleus of animal cells

  • each consists of 2 tubelike proteins organized in 9 groups of 3

• ALWAYS work in a pair

• activate in cell division (mitosis)

• 1 centrosome = 2 centrioles

centrioles

• 2 hollow cylinders that make up a centrosome

Centrosome/centrioles function?

don’t do much bc activate when cells are dividing (cells don’t divide much)

• help form fibers that will control chromosomal movement (like flagella & cilia)