UT Austin Dr. Sata BIO311C Exam 2

Panspermia

Explores whether life came from another planet or not, based on the proposal that meteors from space came with either simple living organisms or the complex molecules needed to start life on earth.

Abiogenises

Life originated spontaneously from simple atoms and molecules combining under high temperature in the presence of water, lightning, limited availability of oxygen, and other conditions of early earth.

Reducing Environment

Favor the adding of electrons and may have helped to form complex molecules from simple molecules. The energy to form complex molecules may have been provided by high temperatures and UV radiation.

Miller and Urey Experiment

Hydrogen, water, methane, and ammonia were added with high power electrodes in order to simulate lightning to provide energy for further reactions. After cooling the reaction products, they noticed that simple organic molecules including urea, organic acids, simple sugars, and amino acids had been formed.

Substratum

In addition to water and a reducing environment, the polymerization of monomers may need a __________ or a solid base for attachment.

Protobionts

Simple monomers and macromolecules can aggregate to form simple structures called __________, which were essential for cells to evolve and to keep internal conditions separate from the surrounding environment.

RNA

What molecule can be used to store information and also to catalyze the synthesis of other molecules?

Domains

Eukara, Prokarya, Archaea

Kingdoms

Protista, Fungi, Plantae, Animalia

Prokaryotic and Eukaryotic

The two types of cells are ___ (without nucleus) and ____ (with nucleus).

Magnification

How big something is in microscopy.

Resolution

How clear something is in microscopy. AKA resolving power, it sets the practical limits of magnification.

Light Microscope

Light is focused on the specimen through a condenser lens, and light passing through the specimen is refracted through the objective lens and ocular lens to magnify the subject. Observes live specimens in their natural colors or with stains.

Transmission Electron Microscope

Electron beams are aimed at a thin section of a specimen stained with metal to absorb electrons and enhance the contrast. Electrons transmitted through the specimen are focused and the image is magnified by electromagnetic lenses. Studies internal ultrastructures and cross-sections of cells or structures.

Scanning Electron Microscope

Electron beams scan the surface of a specimen coated with gold. Scanning beams excite the secondary electrons on the sample surface, which are then collected and focused by the electromagnetic lens. Used to view the surface features and the 3-D shape of ultrastructures.

Centrifuges

Are used to separate solutes in solution by using centripetal acceleration. Denser things go to bottom, lighter things/solute goes to top.

Gel Electrophoresis

Used to fractionate DNA, RNA, or protein molecules. Negative charges on molecules make them migrate towards the anode through tiny pores in the gel. Different sizes move at different speeds.

Bacterial Cells

(prokaryotic) lack nucleus and all other membrane bound structures

Histones

Proteins are attached to DNA

Nucleus

DNA replication, RNA synthesis (transcription) and RNA processing occur inside

Nucleolus

region within nucleus that serves as organizing center for making ribosomes from ribosomal RNA and ribosomal proteins

Ribosomes

Synthesize proteins with their catalytic ability. Are found freely in cytoplasm (to make soluble proteins) or attached to rough ER (to make membrane proteins) as well as in chloroplasts and mitochondria.

Smooth ER

no ribosomes attached, synthesizes lipids, participates in carbohydrate metabolism, detoxifies unwanted chemicals including drugs, stores calcium ions necessary for muscle contraction

Rough ER

ribosomes attached for membrane protein synthesis, synthesizes membrane-bound proteins for secretion and modification, and synthesizes membrane from phospholipids and membrane proteins

Golgi Apparatus

Functions as the central receiving and dispatching center where proteins made in the ER arrive, are sorted out, packaged into vesicles and shipped to target sites. CIS side receives, TRANS side ships.

Lysosomes

Membrane bags with hydrolytic enzymes that can break down all four kinds of macromolecules. Only active at certain pH (5.0). Digests food, microorganisms, or organelles while excreting digested material into cell if wanted or outside if not needed.

Peroxisomes

Responsible for lipid degradation and detoxification of active oxygen species.

Glyoxysomes

Are specialized peroxisomes in plants that facilitates breakdown of storage lipids in germinating seeds that store large quantities of oils and lipids.

Large Central Vacuole

Present only in plant cells, stores organic compounds, inorganic ions, metabolic byproducts, waste products, lytic enzymes, pigments, and water

Food Vacuole

Helps primitive animals ingest food by endocytosis, fuses with lysosomes prior to digestion

Contractile Vacuole

In fresh water protists, helps remove excess water from the cell

Mitochondria

found in all higher eukaryotes, cellular respiration, make ATP, have double membrane structure, own DNA and proteins, replicate autonomously

Chloroplasts

plants only, photosynthesis and amino acid biosynthesis, make ATP, have double membrane structure, own DNA and proteins, replicate autonomously, contains green and other color pigments

Leucoplast

colorless plastids that perform amino acid biosynthesis

Amyloplast

starch-storing plastids

Chromoplast

contains color pigments and ma perform photosynthesis and amino acid biosynthesis or they simply store color pigments

Cytoskeleton

made up of microfilaments, intermediate filaments, and microtubules

Dynein

attached to one set of microtubules and help in sliding on another set of microtubules; involved in ciliate and flagellate movement

Kinesin

helps in the movement of vesicles on the tracks of microtubules

Microtubules

hollow tubes containing tubulin protein, help in cell motility, maintain cell shape, chromosome movement, and serve as tracks for movement of organelles

Microfilaments

solid rods of intertwined strands of actin, help in cell motility, cell shape & change, muscle contraction, cytoplasmic streaming in plant cells, cleavage furrow

Intermediate Filaments

hollow tubes made up of heterogeneous proteins, help in structural support, tensile strength, cell shape, anchoring the nucleus and other cell organelles, and the formation of nuclear lamina

Cell Wall

only found in bacteria, fungi, some protists and plants. Those found in plants contain polysaccharides such as cellulose. Protect cells, give physical support and help in water conservation. Layered from outside in: middle lamella, primary cell wall, secondary cell wall, and plasma membrane.

Plasmodemsata

Pores in plant cell walls which are important for cell to cell transport and viral movement.

Tight Junction

two cell membranes are fused by integral membrane proteins to prevent movement of any solutes through the space between

Gap Junctions

Connections between two cells through connexons, channels through which chemical signals or solutes can pass from one cell to another, important for cell to cell communication

Desmosomes

Spots where two cells are connected together by keratin like fibrous proteins, contains cytoplasmic protein plaques (raised areas); not as tightly sealed as tight junctions, some space exists between adjacent celles.

Integral Protein

AKA intrinsic proteins traverse the membrane

Peripheral Proteins

AKA extrinsic proteins are bound to proteins on the surface

Ion Channels

Specific membrane proteins facilitate the transport of charged ions and molecules across the membrane

Uniport

a type of transport protein that moves a single solute in one direction, H+ pump

Symport

a type of transport protein that moves two solutes in one direction, sucrose/H+ pump

Antiport

a type of transport protein that moves two solutes in opposite directions, Na+/H+ pump

Passive Transport

Does not need cellular energy and the transport happens from high to low concentration

Active Transport

Requires energy in form of ATP, light or electrons. It transports against concentration gradient, from low to high concentrations.

Osmosis

Diffusion of water from high concentration to low concentration through a selectively permeable membrane.

Isotonic

same water concentration, animal cells are stable, plant cells are flaccid

Hypertonic

high water concentration in cell, animal cells shrivel, plant cells are plasmolyzed

Hypotonic

low water concentration in cell, animal cells lysis (burst), plant cells are turgid

Facilitated Transport

Is the passive transport of molecules through an integral membrane protein specific for each type of solute.

Coupled Transport

(Cotransport) a form of active transport where a primary active transport system is coupled with another transport secondary active transport that does not use ATP but depends on the primary active transport.

Exocytosis

Vesicles from the ER or Golgi bodies carrying macromolecules and other materials to be secreted fuse with the plasma membrane and open outside to secrete materials.

Phagocytosis

Macrophages engulfing bacteria that is identified for destruction.

Pinocytosis

Refer to cells gulping droplets of extracellular fluid.

Receptor-mediated endocytosis

Specific receptor proteins recognize large molecules, change conformation, and engulf low density lipoproteins containing these molecules and related proteins into the cell for processing.

Intracellular Communication

communication that occurs within the cell itself

Intercellular Communication

communication that occurs between cells located close to or far from each other

Paracrine Signaling

(local signaling) communicated by the cell surface proteins on the plasma membrane of the signaling cell to the receptors on another cell located close by

Endocrine Signaling

(hormonal signaling) signaling from endocrine cells to cells located far away

Synaptic Signaling

signaling between nerve cells

First Messengers

Signaling molecules such as hormones, proteins, ions, and other chemical signals that must be present nearby or generated by the cell

Signal Reception

Step 1: First messenger can be recognized by specific receptors. The signal activates the receptor which activates the signaling pathway inside the cell.

Signal Transduction

Step 2: Inside the cell, the signal is converted by activating another protein which may activate yet another protein and start a cascade of signaling pathways.

Cell Communication

Three steps: signal reception, signal transduction, and cell response

Second Messengers

compounds that can be generated during signal transduction, creating cascades, occurring inside the cell

Cellular Response

Step 3: once the signaling pathway is activated, the cell or organism responds through increased gene expression and metabolic activity, growth, defense, and movement

Phosphorylation Cascade

The binding of the first messenger to the receptor results in the phosphorylation of the receptor itself or the proteins/enzymes associated with the receptors. This is a common mode of activating several enzymes in a phosphorylation cascade for a rapid response to a signal.