Model 2 examine

Cell

Structural units of living things

Human cell have 3 main parts

Plasma membrane

Cytoplasm

Nucleus

Plasma membrane

Outer boundary of the cell

Bilayer is constructed mainly of phospholipid with small amount of cholesterol. Two types Of proteins: transmembrane and peripheral

Cytoplasm

Fluid packed with small structures that perform specific functions (organelle)

Nucleus

Controls cellular activities

The plasma membrane structure

Define the boundaries of the cell

Fluid mosaic model

Membrane is thin structure, composed of double layer or lipid bilayer, proteins form constantly change mosaic pattern

The plasma membrane function.

Membrane transport

Selective permeability

Nutrients must enter the cell - undersirable materials must be kept out

valuable cell proteins must be kept within the cell - waste must pass out the cell

What are the subtances pass through the cell membrane by?

Passive processes and Active processes.

Passive processes

Without energy input, also we have Diffusion, Simple Diffusion and Facilitated DIffusion.

Diffusion

Molecules diffusion “down their concentraction grandient”. That is going from high consentraction to low consentration.

Lipid bilayer of plasma membrane = barrier to free diffusion unless the molescules is 1) lipid-soluble, uncharge (nonpolar). 2) very small

Simple Diffusion

“Nonpolar and lipd-soluble” subtances diffuse directly through the lipid bilayer,

Subtnces include: Oxygen, Carbon dioxide, Fat-soluble vitamins, alcohol and store

Facilitated Diffusion

Polar and charged subtances are transported by proteins carrier molecules in the plasma membrane

subtances include: simple sugar (glucose), Ions (Na+,Cl-)

Osmosis

Diffusion of water (only) trough selctively permeable membrane

Occurs when concetractions differ on two side of the membrane.

Tonicity

Ability to a solution to change tone or shape of the cells by altering internal water volume.

Isotonic

Neutral, solutions with same consantraction of solutes as those in the cell (0.9% saline, or 5% glucose)

Hypertonic

Shrink, solution with higher concentralction of solute. solutions is going out of the cells

Hypotonic

Swell and burst, sloutions with lower concentraction. solutions is goin into the cells.

Active processes

Cell uses energy from (ATP) to move solutes across the membrane agains its concentranction grandient.

Active processes major mechanisms

Sodium-potasions Pumps, K+ potancium → 2 goins in → Na+ sodium → 3 go out

Exocytosis Vasicular transport

Moves subtances out of the cells. moves wastes out of vasicular cell.

Endocytosis Vesicular Transport

Allows paricules to enter the cells. somtimes involves receptors like Receptor-mediated endocytosis.

What kind of cell are out there?

Animal cell , plant cell, and human cell

Cell cycle

Set of stages during wich DNA double and divide into 2 genetically identical daugater cells. Cell division

Cell Division

Interphases = growth and prepare to divide.

Mitosis = nucleus divides followed by the cell itself.

The nucleus

Contral center of the cell, DNA = genetic library, Dictates kinds and amounts of protains to be synthesized

DNA - code to proteins

Ribosomes

Small particle made of protein and RNA, proteins factory, sites for protein synthesis

make proteins pumps membrane, signal, enzymes.

Endoplasmic Reticulum

Rough ER = have attached ribosomes for proteins production, a fall blacked

Smooth ER = no ribosomes synthesizes lipids. liver has this and they deal wirth lipids breaking down or deal with fat

Proteins Synthesis

Interphase, Transcription, and translation.

Interphase

the cell carries on regular activities

Transcription

RNA - polymerase = nucleutides

DNA to mRNA

Making copy or taking notes on the DNA → then pre-mRNA to the nuclediotide

Translation

Ribosome / mRNA to proteins

In here Ribosome read and translated to make aminno acid = proteins.

Nucleotides

Adenine, Guanine, Thymine, Cytosine → transcription = RNA polymerase → Adenine, Guanine, Uracil, Cytosine → translation = ribosome → make amino Acid 20 different AAs.

Golgi Apparatus = FedEx

Stacked, flattened membranous stacks, principal traffic director for cellular proteins, major functions = modify, concentrate and packege proteins and membranes made at hte rough ER. Madesure that is delivery to where the proteins need to be.

Lysosomes

Contain digestive enzymes, Abundant in phagocytes, sites where digestion can proceed safely, where cell go tto die.

DNA replication

DNA polymerase

Resulting in two identical DNA double-strands

Mitosis

The devision of genectic material, during which the cell nucleus breaks down and two new, fully functional, nuclei are formed.

Prophase

1st phase = centrososmes moves toward opposites poles

Metaphase

2nd phase = the chromosomes are line up

Anaphase

3rd phase = centromeres split in to two

Telophase

4th phase = Chromosomes arrive at opposite poles and begin to decondense

Cytokinesis

Final pahses = when separates the daughter cell

Mitochondria

Power plants of the cell - provide most of the ATP supply, “powerhouse”. Density of mitochodria reflects cell’s energy requirement. Enclosed by two membrane. Contain its own DNA and RNA

Histology

Study of the body tissue

Tissues

are composed of specialized cells of similar structure and perform a common funtion.

Epithelial tissues

Cover outside and line inside body surfaces

cover/protect : absortion and some secreation

Mitotic

Readily divide to replace lost or damaged cells

Simple Squamous Epithelial tissue

Location: lines air sacs of lungs and blood vessels

Funtion: Filtration, diffusion

Stratified Squamous Epithelium tissue

(non-keratinized0

Location: mouth, anus, vagina and esophagus

Function: protection, barries

Stratified Squamous Epithalial Tissues

(keratinized)

Location: skin

Function: protection, barrier

Simple Cuboidal Epithelium Tissues

Located: Kidneys and glads “oil, skin”

Function: Secretion, absorption

Simple Columnar Epithelium Tissues

Located: GI tract, desatric tract

Funtion: secretion, absortion

Pseudostratified Columnar Epithial Tissues

Located: lines trachea and fallopian tubes

Function: movement of mucus and cells

Connecive Tissue

Binds structures together, provides support and protection, fill spaces, produces blood cells and stores fats.

contain fibers.

Areolar CT

Location: between tissue / organs

Function: binds tissues / organs together

Adipose CT

Fat = lipid - stored faster energy

Location: beneath skin; around organ

Function: protect organs, source of stored energy

Fibrous CT

Dense Regular CT

Location: tendons, ligament

Function: connect muscle to bones, connect bones to bones

Fibrous CT

Dense irregular CT

Location: dermis of skin

Function: protection, barrier

Cartilage CT

Location: nose, ends of bones, rings of trachea

Function: structural support

Bones CT

Location: bones of the skeleton

Function: support, protection, storage, locomotions, blood cell production

Blood CT

Location: blood vessels

Function: supplies cells with nutrients and oxygen, takes away wastes, fights, infection

Muscle Tissues

Contract to provide movement, some are under voluntary contract, while others contract involuntary

Skeletal Muscle

Location: attaches to bones/skin

Function: voluntary contract, usually for movement of the skeleton

Cardiac Muscle

Location: heart walls

Function: involuntary contraction, pumps blood

Smooth Muscle

Location: hollow organs of anytypes, walls of hollow organs

Function: involuntary contraction, moves contents of hollow organs

Nervous Tissues

Location: Brain, spinal cord, nerves

Function: conduct electrical signals to communicate within and control the body

Include - neurons, Glial cell, neuroglia