Kendrick: Unit 2 Test Review

Mix of units 2 and 3, little of 4

Cytology

The structure and function of cells

Light Mircoscope

Based on light passing through a two-lens system. Can view prokaroyitic and eukarotics cells but not virssuse.

Magnification

Ability to enlarge the image

Resoltuion

Ability to provide clarity to the image

Electron Microscope

Uses a beam of e- to provide greater magnification and resolution

Transmission Electron Microscope (TEM)

Used to view the internal components of cells (organelles)

Scanning Electron Microscope (SEM)

Used to view the surface of cells

Cell Fractionation

The ability to use centrifuges to spin at different high speeds to fractionate (split apart) cells

Prokaryotic Cells (P)

No nucleus. Unicellular bacteria. Contains ribosomes, cytosol, cell wall

Differences between prokaryotic and eukaryotic cells

Nucleoid Region

Devoid of a true nucleus, DNA floating in cytoplasm

Cytoplasm

Material and area designating the inside of the cell

Cytosol

Fluid inside the cell (only in prokaryotes)

Ribosomes

Location of Protein synthesis

Capsule

Lies outside the cell wall, is made of carbohydrates and is pathogenic (disease causing)

Eukaryotic cells (E)

Has a nucleus. Animal/Plant cells, all multicellular, some unicellular eukaryotic cells (fungi)

Nuclear envelope (E)

Double memberane made of phospohilpids and proteins.

Nuclear Pores (E)

Holes that allow transportation of materials

Nuclear Lamina (E)

Set of proteins that give the nucleus its structure

Chromosomes (E)

Uncoiled chromatin that contains genes

Chromatin (E)

DNA and proteins combine within the nucleus, coiled DNA

Nucleolus

Inside the nucleus, a location where ribosomes are synthesized

Ribosomes

Found outside the nucleus and where protein synthesis occurs. The only organelle found in BOTH prokaryotes and eukaryotes.

Organelles found in ANIMAL cells, not PLANT cells

Centrioles, Flagella, Lysosomes, Intermediate Filaments

Organelles found in PLANT cells, not ANIMAL cells.

Cell Wall, Central Vacuole (anima cells have vacuoles but not a central one), Chloroplast, Plasmodesmata

Cell membrane

Made of phospholipids (have a hydrophobic and hydrophilic region). Are not static, always moving. Semi-permeable: Some molecules can go through. Controls what goes in and out of the cell.

Fluid Mosaic Model of Membranes

The membrane is a mosaic of proteins that float around the phospholipids.

Cholesterol (Membrane)

Found in membranes and assists the membrane to be less fluid

Integral Proteins

Transmembrane proteins with hydrophobic and hydrophilic portions

Peripheral Proteins

Bind to the integral proteins on the outside of the cell membrane

Functions of membrane proteins

Transportation, Enzymatic activity, Signal transduction and cell communication, cell to cell contact and attachment

Membrane Trafficking

• Small molecules that are both hydrophobic and nonpolar molecules such as O2 and CO2 can cross the membrane with ease

• Large and charged molecules undergo selective permeability with respect to the membrane

Transport Proteins

Proteins that aid is moving molecules across the membrane

Diffusion

Tendency for molecules to move from a higher concentration to a lower concentration. The flow of solute particles through a selectively permeable membrane. NO ENERGY

Passive Transport

Diffusion across a biological membrane

Osmosis

Diffusion of water across a membrane. During Osmosis water flows from a hypotonic to a hypertonic soln.

Hypotonic

A solution that has a lower concentration of solute compared to the cell. Hypotonic cells will eventually swell and burst. PLANT cells prefer a hypotonic environment.

Isotonic

Solutions that contain the same concentration of water and solutes as the cell cytoplasm. Cells placed in an isotonic solution will neither shrink nor swell since there is no net gain or loss of water. ANIMAL cells prefer an Isotonic solution.

Hypertonic

A hypertonic solution has a higher solute concentration compared to the intracellular solute concentration. Neither plant nor animal cells like hypertonic solutions. if a cell is placed in a hypertonic solution, it with shrink/shrivel and die.

Facilitated Diffusion

Movement of molecules (usually polar) across the membrane with the aid of membrane transport proteins. This is passive transport so no energy (ATP) is required.

Active Transport

Movement against the conc. gradient, requiring ATP

Cotransport

Coupling of the movement of molecules into and out of the cell at the same time

Exocytosis

Fusion of vesicles and molecules with the plasma membrane secreting materials to the outside of the cell

Endocytosis

The cell takes in molecules using vesicles

Phagocytosis

Cell engulfs molecules, most commonly involved in immunity

Pinocytosis

Cell drinking, taking in fluids or small molecules

Receptor Meditated endocytosis

Specific sites on the membrane bind to specific molecules on the outside, engulfing them into the cell

Endomembrane System

The different membranes that are within the cytoplasm of a eukaryotic cell

Endoplasmic Reticulum (ER)

Joins the nuclear envelope. Contains the smooth and rough ER.

Smooth ER

The smooth ER lacks ribosomes. Synthesis of lipids and carbohydrates. Detoxification of drugs in the body (why the liver is one of the most important organs in the body). ribosomes

Rough ER

Synthesis of proteins and new membranes. Site of the convergence of mRNA, tRNA, and rRNA.

Golgi Apparatus

• The global shipping and manufacturing area of the cell

• Modification of molecules such as proteins takes place

• Secretion of proteins to other parts of the cell or other cells

• Synthesis of carbohydrates

Lysosome

From Golgi body. Contains hydrolytic enzymes that break down macromolecules. Enzymes in the lysosome work best at low pH range. Aid in phagocytosis and intracellular digestion,

Food vacuoles

Store broken down macromolecules

Contractile vacuoles

Found in protists and releases water allowing contraction and expansion.

Mitochondria

Organelle that produces ATP (energy). Requires oxygen and is enclosed in an envelope of two membranes.

The endosymbiotic theory

The theory is that the mitochondria and chloroplasts were once prokaryotes. As they have their own DNA and divide by binary fusion.

Cristae

Components of folded inner membrane in the mitochondria.

Intermembrane space

Mitochondria matrix

Chloroplasts

Site of photosynthesis in plant cells. Has its own DNA and can produce ATP by the light rxn of photosynthesis.

Thylakoids

Membranous sacs inside chloroplasts

Granum

Stacks of thylakoids

Stroma

Fluid area outside of the grana

Peroxisome

The membrane-bound organelle that transfers hydrogen from compounds to make hydrogen peroxide H2O2

Volume to surface area

As volume gets bigger, surface area gets smaller

Cytoskeleton

A variation of fibers (mostly proteins) that can cover the entire cell. three main types of fibers; Microfilaments, Microtubules, and Intermediate Filaments.

Mircotubles

Made of alpha and tubulin protein, involved in mitosis

Centrosome

Organelle near the nucleus that produces microtubules

Centrioles

Made from the centrosome contains a 9+3 configuration

Cilla

Short and numerous which increase surface tension. Along the surface of the cell and moves stuff along.

Flagella

Long tail propel movement

Microfilaments

These are thin, thread-like structures made of actin protein that play a crucial role in cell shape, movement, and division. They are involved in muscle contraction, support the cell's cytoskeleton, and help in the transport of materials within the cell. Their dynamic nature allows them to grow and shrink rapidly, responding to the needs of the cell.

Intermediate filaments

Made of keratin proteins. Reinforces the cell’s shape and positions organelles in their proper place in the cells.

Extracellular Matrix

Glycoproteins (proteins attached to carbohydrates). Aids in communication of cells and, cell to cell adherence. Positions organelles in the proper place within the cell.

Collagen

Glycoprotein in extracellular matrix