Anatomy and Physiology Lab Exercises 3&4

Cell

The structural and functional unit of all organisms

Plasma membrane

Forms the outer boundary of a cell

Nucleus

• Cell’s control center

• Where DNA is housed

Cytoplasm

Relatively clear area between the nucleus and the plasma membrane

The Plasma Membrane

• Consists of two layers of phospholipid molecules

• the membrane is flexible

Selective Permeability

Allows some molecules to pass through while preventing the passage of others

Receptors

• Receive chemical signals from other cells

• enable communication between cells

Channel proteins

• Allow passage of water and solutes

• some are always open

• others open and close under different conditions

Carrier proteins

Actively transport substances into, or out of, the cell

Identity markers

Serve as an identity tag so other cells can distinguish between self and foreign cells

Enzymes

• Catalyze reactions that break down specific molecules

• Make chemical reactions in the cell

Attachment proteins

Attach cells to each other or to extracellular material

The Nucleus

• Large spherical organelle

• surrounded by the nuclear envelope

Nuclear matrix

Contains and organizes chromosomes

Chromatin

Formed between DNA and proteins to help keep the chromosomes in the nucleus

The Cytoplasm

Lies between the nucleus and the plasma membrane

Cytosol

• Liquid portion of the cytoplasm

• Fills the cell and gives it shape

• Allows nutrients to move about the cell

• Cellular functions are primarily performed by the organelles

Endoplasmic Reticulum (ER)

• Rough Endoplasmic Reticulum (ER) - Involved in protein synthesis and sorting

• Smooth Endoplasmic Reticulum (SER) - Detoxification, carbohydrate metabolism, calcium balance, synthesis, and lipid modification

Ribosomes

• Composed of RNA

• Serves as sites of protein synthesis

Golgi Apparatus

• Stack of flattened, membrane-bounded compartments

• Vesicles transport materials between stacks

• Secretion, processing, and protein sorting

Mitochondria

• Powerhouse of the cell

• Site of ATP synthesis

• Has their own DNA

Lysosomes

• Contain digestive enzymes

• Digests molecules or entire cells

Interphase

• Maintenance (resting) phase between cell divisions

• Preps the cell for division

Mitosis

• Cells divide to produce two daughter cells from a single parent cell

• Facilitates the growth of an organism

Cytokinesis

• The division of the parent cell into two daughter cells

• Forms a cleavage furrow

G1 phase

Cells growth

S Phase

• Chromosomes Replicate

• Chromosomes stay connected to each other and are called Sister Chromatids

Before S phase

46 chromosomes and 46 chromatids

After S phase

46 chromosomes and 92 chromatids

G2 Phase

• Cell synthesizes protein needed during mitosis and cytokinesis

• Checkpoint to see if DNA has been correctly copied

Prophase

Nuclear Membrane Dissociates

Metaphase

Chromosomes are aligned along the metaphase plate

Anaphase

• Chromosomes split

• Individual sister chromatids moved towards opposite poles of the cells

Telophase

• Chromosomes have reached their respective poles

• Nuclear membranes reforms

Cytokinesis

The cytoplasm is divided into two daughter cells

Brownian Movement

• Random movement of particles in a liquid or gaseous state

• Caused by collisions with molecules of the surrounded medium

• Inside and out the cell there are particle with thermal energy

Diffusion

• Movement of solutes from high to low concentration

• Can happen in gas and liquid phases

• Affected by temperature and molecule size

Osmosis

• Movement of solvent molecules (Water) from low to high solute concentration

• Diffuses through a semipermeable membrane

Isotonic

Equal water and solute concentrations on either side of the membrane (what is inside IVs)

Hypertonic

Solute concentration is higher (water concentration is lower) on one side of the membrane (water will leave cell & cell shrinks)

Hypotonic

Solute concentration is lower (water concentration is higher) on one side of the membrane (way too much water & burst cells) (you can give a hypotonic iv to remove excess fluid as waste)

Cytoplasm

All the space apart from the organelle

Microtubules

1. Give cell structure

2. Transport

3. Form backbone of organs

Mitochondrion

Turns glucose into ATP

Ribosome

Makes Proteins

Rough ER

Contains rough ribosomes