Flashcards UCONN Bio Chapters 6-9 & 11

Light Microscope

(LM) when visible light is passed through a specimen and then through a glass lens causing the specimen to be magnified

What are the three parameters of microscopes?

-magnification

-resolution

-contrast

Magnification

the ratio of an object's image size to its real size

Resolution

a measure of the clarity of an image

contrast

accentuates differences in parts of the sample

organelles

membrane-enclosed compartments that are too small to be resolved by a light microscope

electron microscope

(EM) when a focused beam of electron is put through a specimen or onto its surface.

cell ultrastructure

the cellular anatomy revealed by an electron microscope

scanning electron microscope

(SEM) a microscope that is used for detailed study of he surface of specimen.

transmission electron microscope

(TEM) used to study the internal ultrastructure of cells.

cytology

the study of cell structure

Chromatin

genetic material formed by DNA and proteins, forms into chromosomes. Only present in Eukaryotic cells

biochemistry

the study of molecules and chemical processes of cells

cell fractionation

the taking apart and separating of cells into major organelles and other subcellular structure. Done on a centrifuge

What parts do all cells have?

-Plasma Membrane

-Cytosol/cytoplasm

-chromosomes + DNA

-Ribosomes

plamsa membrane

a selective barrier that surrounds all cells

cytosol

a semifluid jelly-like substance in a cell where organelles and other components of the cell are found.

chromosome

the part of the cell that contains genes and DNA

ribosomes

where protein is made via instructions from genes in the cell

eukaryotic cell

cells where most of the DNA is stored in the nucleolus and the nucleolus is surrounded by a double membrane

prokaryotic cell

cells where DNA is concentrated in the nucleoid and is not surrounded by any membranes.

nucleoid

a ball of DNA that is how prokaryotes store their DNA

Cell Wall

extracellular structure that protects the cell, maintains shape of the cell, and prevents excess uptake of water. Not present in animal cells

Plasma Membrane

selective semipermeable barrier that lets in oxygen and nutrients. In all cell types

cytoplasm

the interior of a prokaryotic cell

nucleus

where most of the genes in eukaryotic cells are located and one the largest organelles in the cell. Not present in Prokaryotes

nuclear envelope

a double membrane that encloses the nucleus and separates its contents from the cytoplasm.

double membrane

when two membranes are separated by a space of 20-40mm

pore complex

a protein structure that lines each pore on the nuclear membrane and regulates the entry and exit of proteins and RNA as well as large macromolecules

nuclear lamina

a net like array of protein filaments that maintains the shape of the nucleus by supporting the nuclear envelope

chromotin

proteins and DNA that make up the chromosomes

Nucleolus

Organelle found inside the nucleus and produces ribosomes

Ribosomes

site of protein synthesis. Made of ribosomal RNA (rRNA) and proteins. In all cell types

Free Ribosomes

ribosomes that float in the cytoplasm and make proteins for use within the cell. Found in both Eukaryotic and Prokaryotic cells

Bound Ribosomes

ribosomes attached to the endoplasmic reticulum and make proteins destined for membranes, secretion, or other organelles

Endomembrane System

a network of interconnected membranes and organelles that work together to modify, package, and transport proteins and lipids.

What does the endomembrane system include?

-Nuclear envelope

-Endoplasmic reticulum (rough and smooth)

-Golgi apparatus

-Lysosomes

-Vesicles

-Plasma membrane

What is the flow of materials throughout the endomembrane system?

1. Proteins synthesized on rough ER

2. Transported in vesicles to Golgi Apparatus

3. Modified and sorted in Golgi Apparatus

4. Packaged into vesicles for final destinations

5. Delivered to plasma membrane, lysosomes, or secreted

Vesicles

small membrane sacs that specialize in moving products into, out of, and within a cell. Move along the cytoskeleton

Endoplasmic Reticulum

(ER) an extensive network of membranes that carries proteins throughout the cell. Continuous with the nuclear envelope. Only present in Eukaryotic cells

Rough ER

region of the ER that has ribosomes on it and looks rougher under a microscope. Synthesizes membrane proteins and secretory proteins and is the initial protein folding and quality control

Smooth ER

region of the ER that synthesizes lipids, metabolises carbohydrates, detoxifies drugs and poisons, and stores calcium ions.

Glycoproteins

proteins that have carbohydrates covalently bonded to them

Transport Vesicles

Vesicles in transit from one part of the cell to another.

Golgi Apparatus

where many transport vesicles travel to. Where products of the ER and modified, stored, and then sent to other parts of the cell. Only in Eukaryotic cells

Cis Face of the Golgi Apparatus

the receiving side

Trans Face of the Golgi Apparatus

the shipping side

Lysosomes

cell organelle filled with enzymes needed to break down/digest certain materials in the cell such as macromolecules, food particles, old organelles, and even the entire cell during programmed cell death. Interior is acidic (pH ~5) to facilitate its enzymes.

Centrosome

a region of the cell often near the nucleus which microtubules grow out from. only in animal cells

Food Vacuoles

vacuoles that store food and are formed by phagocytosis

Contractile Vacuole

pumps excess water out of the cell to make a stabile concentration of ions and molecules. Found in freshwater protists

Central Vacoule

a vacuole that mature plant cells contain. Can hold organic compounds and water.

Vacuoles

storage compartments for cells

Selective Permeability

allowing some substances to cross more easily than others

Amphipathic

a molecule with both a hydrophobic and hydrophilic region such as a phospholipid

Fluid Mosaic Model

how phospholipids are arranged with proteins in a cell wall with the lipids being the "liquid" and proteins dotted throughout

Integral Protiens

proteins that penetrate the hydrophobic core of the phospholipid bilayer

What proteins are found within the cell membrane?

-integral proteins

-peripheral protiens

Peripheral Proteins

proteins on the surface of the cell membrane/phospholipid bilayer. often involved in signaling or maintaining cell shape

Cell-Cell Recognition

the ability for a cell to distinguish one type of neighboring cell from another. Important for sorting cell into tissues and orgnas

Glycolipids

when membrane carbohydrates covalently bond to lipids

Glycoprotiens

when membrane carbohydrates covalently bond to proteins

Transport Proteins

proteins that span the membrane and allow for hydrophilic substance to pas through the lipid bilayer. Can be used in both passive and active transport

Aquaporins

channel proteins that allow water to pass through the cell membrane

Channel Protiens

transport proteins that certain atomic ions can ues a tunnel through the cell membrane

Carrier Proteins

transport proteins that hold onto their passengers and change shape in a way that shuttles them across the cell membrane

Diffusion

the movement of molecules of any substance so they spread out evenly onto the available space. Does not use any energy and its rate depends on temperature, molecule size, and concentration gradient

Concentration Gradient

the movement of a substance from high to low concentration

passive transport

the diffusion of a substance across a biological membrane that does not use energy

Osmosis

the diffuse of water across a selectively permeable membrane from an area of lower solute concentration to higher solute concentration. Requires no energy

Tonicity

the ability of a solution to cause a cell to gain or lose water depending on the concentration of the solute

Isotonic

when the concentration of a solute is equal in and out of the cell

Hypertonic

when the concentration of a solute is greater outside the cell than inside

Hypotonic

when the concentration of a solute is greater inside the cell than outside

Osmoregulation

the ability to control solute concentration and water balance

Turgor Pressure

the pressure that is exerted on the inside of cell walls and that is caused by the movement of water into the cell

Turgid

when a cell is very firm from being full of water. Healthy state for plant cells

Flaccid

when a cell becomes limp because of lack of water. Causes the wilting of a plant

Plasmolysis

when a plasma membrane pulls away from a cell as it shrives becomes of lack of water. Causes a plant cell to die

Facilitated Diffusion

passive transport of substances across a membrane with the help of transport proteins, moving down the concentration gradient.

Ion Channels

channel proteins that transport ions

Gated Channels

ion channels that open or close in response to stimulus

Active Transport

Movement of substances across a membrane against their concentration gradient (from low to high concentration), requiring energy. Uses carrier proteins (often called pumps)

and allows cells to maintain concentration gradients

Sodium-Potassium Pump

a transport system that exchanges Na+ (sodium ion) for K+ (potassium ion) across the plasma membrane of animal cells

Voltage

electrical potential energy that all cells have across their plasma membrane

Membrane Potential

the voltage across a membrane

Electrochemical Gradient

the combination of chemical forces (concentration gradient) and electrical forces (membrane potential) on an ion

Electrogenic Pump

a transport protein that generates voltage across a membrane

Proton Pump

the main electrogenic pump of plant, fungi, and bacteria. Actively transports protons (H+) out of the cell

Cotransport

also known as secondary active transport. When one substance moves down its gradient, powering another substance against its gradient. Uses energy stored in an existing concentration gradient

Exocytosis

When vesicles fuse with plasma membrane and release contents outside the cell. Used for secretion and waste removal

Endocytosis

Movement of materials into the cell by forming vesicles from the plasma membrane.

What are the types of Endocytosis?

-phagocytosis

-pinocytosis

-receptor-mediated endocytosis

Phagocytosis

"cell eating" when a cell engulfs a particle and packages it with a food vacuole

Pinocytosis

"cell drinking" when a cell "gulps" droplet of extracellular fluid into tiny vesicles formed by folding the membrane. Nonspecific and takes in whatever is dissolved in the fluid

Receptor-Mediated Endocytosis

when specific molecules bind to receptors on membrane. Then, coated pits form and pinch off as coated vesicles. Highly selective

Metabolism

the total of an organism's chemical reactions

Metabolic Pathway

when a specific mole is altered in a series of steps resulting a certain product. Each step is catalyzed by a specific enzyme

Catabolic Pathway

the breaking down of complex molecules to simpler compounds to release energy

anabolic pathways

when energy is consumed to build complex molecules from simpeler ones