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

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

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

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

cytosol 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