Bio 311 C

will not be found in plant root cells but will be found in plant cells located in the upper surface of leaves which are exposed to sunlight.

(beginning) chloroplast

Endoplasmic Recticulum (ER)

- "factory" for producing and cell membrane - Heart of endosomal membrane system: a network of interconnected organelles. - attached to the ear membrane - tubes/sacs called cisternae - enclosed space called the ER is lumen Rough ER: attached ribosomes for protein synthesis (bound ribosomes) - Ribosomes bind RNA in the cytoplasm and manufacture proteins across the ER lumen. - Other proteins are released into the ER lumen and end up inside other organelles, such as lysosomes and vacuoles, or leave to the cell by secretion through the plasma membrane. Secretion of proteins, antibodies/digestive enzymes. - Smooth ER -lack ribosomes - produce membrane and hormones that have enzymes for detoxifying drugs and poison. - Transitional ER - found where vesicles are produced to carry membranes and proteins to other parts of the cells, such as the Golgi app.

Prokaryotes

- Bacteria, archaea - Single, outer plasma membrane - No internal membrane-bound compartments in the cytoplasm - The movement caused by flagellum (motor structure) - External cell wall made of sugars and amino acids polymers called peptidoglycan (protection) - Cytoplasm lacks organelles - DNA found in a region called the nucleoid body. (membrane) - DNA is naked (not in the nucleus) - Perform respiration - Photosynthesis some (ex: cyanobacteria) - DNA & RNA - transcription and translation occur in the cytoplasm of bacteria

Carrier Proteins

- Bind specific molecules - CHANGE SHAPE (one at a time) - Allow the molecule to move to the interior of the cell - Move specific molecules down a concentration gradient by changing shape - Glucose is waiting outside cell, only glucose (alpha) can change shape of proteins - high (out) to low (in)

Alpha

- Branch - Hydroxyl (OH) on bottom - Glycogen in starch

Electrochemical gradient

- Combination of both a concentration and electrical gradient - A form of potential energy for the cell - cytosol to matrix - lower pH means lots of protons

Rate of Diffusion and Concentration Gradient

- Cooler temp = decrease in rate of diffusion - No concentration gradient = no rate of diffusion - Rate of Diffusion must be = to 0 if no concentration gradient QUESTION why level out? - Protein transport sites are saturated with glucose

Osmosis (passive)

- Diffusion of water through a selectively permeable membrane - From low concentration to high concentration

facilitated diffusion (passive)

- Facilitated by specialized transport proteins - Includes osmosis of H2O and regulated movement of ions and larger molecules - Requires membrane proteins - Driving force? Concentrated Gradient - Occur through transmembrane proteins MOLECULES THAT UNDERGO FACILITATED DIFFUSION - Ions - Macromolecules - Sugars - Water (all polar and have a charge) - These move across hydrophobic part of membrane (protein transport) but will not allow polar molecules to move across - polar molecules such as ions, macromolecules, sugars, and water travel through transport proteins because the plasma membrane will NOT allow polar molecules to travel through the hydrophobic tail region.

Mitochondria

- Found in eukaryotes - Specialized for the transport of molecules - folds are called: cristae/crista < ATP production occurs here - Inner membrane space, called matrix, contains DNA & ribosomes; maintain mitochondria as well as enzymes involved in energy conversion. - Small space between the 2 membranes is called the intermembrane space - Came from the process of endosymbiosis which is capable of oxidative respiration - Enzymes to utilize food molecules are housed in the matrix and form the kerbs cycle (citric acid cycle) - Females pass it down from gen. to gen.

Nucleus

- In eukaryotic cell - It contains and protects DNA and regulates the interaction of genes with the rest of the cell. - It contains DNA in a complex with packaging proteins (CALLED CHROMATIN - several individual strands, or piles, called chromosomes) - Nuclear envelope membrane - protects genetic material and separates it from the cell cytoplasm. The barrier that prevents unregulated movement access to the genetic material. Double membrane. - Nuclear pores - Regulate the movement of signaling proteins and other molecules across the nuclear membrane and into the nucleus and allowing RNA out of the nucleus. - Nucleolus - Ribosomal RNA is produced and ribosome subunits are assembled. - Ribosomes - Make proteins using information contained in messager RNA, so cells that produced a lot of protein, such as some kind of secretory cells. Cytoplasm > Nucleus 1. Histones - a protein that DNA wraps around 2. RNA polymerase (enzyme) - makes RNA 3. DNA polymerase - makes DNA - contains special strands called chromosomes

Golgi apparatus

- Modifies, sorts and packages proteins and membranes coming from RER also produces polysaccharides "receiving and shipping center" - made of many cisternas, wider receiving side called the "cis" face side. Which receives vesicles containing modified proteins that the Golgi. - modification include the addition of phosphate groups and oligosaccharides - produces polysaccharides such as pectin (in plants) and mucin (in animal cells) some modifications are targeting signals that direct proteins to different cellular destinations - cisternae move from cis to trans- face as their contents are modified instead of remaining static location. Behavior known as "cisternal maturation" - Tertiary and quaternary structure of the Golgi - Packages material and sends them throughout the cell

Beta

- No branching - Hydroxyl (OH) on top

Molecules found in early earth

- No free oxygen "anoxic" - Water vapor - Hydrogen gas - Methane - Ammonia - Hydrogen sulfide - Carbon dioxide

Channel proteins

- Open in response to a stimulus to allow ions to pass into cell - Channel gated - massive flow - Solute movement is always passive - One at a time

3 main cellular responses

- Opening of an ion channel leads to a change in electrical charge. - Alterations in gene expression lead to change in protein synthesis. - Alteration of enzyme activities leads to a change in metabolism.

Cell damage

- Osmosis of water through aquaporin channels can lead to cell damage - Steep concentration gradient faster rate of simple diffusion "linear"

Eukaryotes

- Plants, fungi, algae, animal - Contains organelles - Nucleus (plural, nuclei) contains the cell's DNA - Cytoskeletal - Plants, fungi, and some algae create cell walls containing either chitin (fungi) or cellulose (plants & algae) - Plants and algae contain chloroplasts - Animal cells have cytoskeletal, motile cilia and flagella (locomotion) - More complex and larger - Respiration - Photosynthesis - DNA (in the nucleus) & RNA

Diffusion

- Random movement of molecules towards a state of equilibrium Speed of diffusion determined by - size of molecule - temp of the solution - concentration gradient - small molecules move faster (vice versa) - solutes diffuse independently (dynamic equilibrium) - same # on each side

3 steps of cellular response

- Reception of the signal - Transduction of the signal (intermediate steps) - Cellular response

Cycle of first things on earth

- Reducing atmosphere - No 02 gas = no oxidation reactions (reducing atmosphere contains these)> - Inorganic molecules - CO2, H2O, NH3, H2S, PO4^-3, CH4 (reactions occur) - Lighting volcanoes radiant energy (sunlight) (formed) - Amino acids, simple sugars, nucleotides, phospholipids - All cells are heterotrophic (eating other organisms) prokaryotes - Photosynthesis evolves in prokaryotes - Production of 02 gas by photosynthesis - Aerobic respiration evolves in prokaryotes - Endosymbiosis ( one lives inside the other) of aerobic prokaryote (requires oxygen) - Eukaryotic cells evolve (membrane-bound organelles) - Endosymbiosis of photosynthetic prokaryote - Eukaryotic cells with chloroplast (plants)

Active transport

- Requires ATP and specialized transport proteins - Move against a concentration gradient - Makes gradient that life relies on - ATP generated by cellular respiration - active transport restores channels - active transport makes the gradient - low to high concentration - made/makes pH gradient protons

QUESTIONS

- Shorter fatty acid chains with more C=C.... increase membrane fluidity - more kinky= more fluidity - decrease temp. = increase time - decrease membrane fluidity = increase cholesterol to lipid ratio & increase # of proteins - Time it takes for the "hole" to disappear is a measure of membrane fluidity. - proteins glow with laser - cell membranes melt/mix @ higher temps.

Phospholipids

- The ratio of saturated and unsaturated fatty acids tails affect fluidity (viscosity) of membrane - un - hydrocarbon tails with kinks - fluidity - sat - hydrocarbon tails - viscous (thick)

Secondary active transport

- Uses potential energy of ion gradient to transport a different molecule into the cell 1st H+ transported 2nd sucrose transport (need proton gradient) - use active transport to create a concentration gradient - increase rate of sucrose transport? decrease extracellular liquid - decrease pH, increase H+ - more H+ outiside = stronger gradient

Catabolism

Breakdown of complex molecules to simpler products and use that energy to be stored in ATP. - ATP and reductants and heat

Lysosomes

Contain hydrolytic enzymes that break down biomolecules. Acidic interior. - store and concentrate digestive enzymes away from the rest of the cell - help recycle old and damaged organelles and other components in a process called "autophagy"

Organelles

Control the cell growth and producing energy, harvesting energy, getting rid of waste, cell activities, structures in the cell, cellular reproduction

Cholesterol

Forms large part of the cell membrane maintaining stability/fluidity and maintenance of the cell structure. Mediates fluidity (hydroxyl (OH) @ end) - Stabilizes the membrane - Breaks up hydrophilic interactions between fatty acids - Ratio of C sat vs unsat pi affects membrane fluidity

What is the difference between "free" ribosomes and "bound" ribosomes?

Free ribosomes are in the cytoplasm, whereas bound ribosomes are anchored to the endoplasmic reticulum. Free ribosomes produce proteins in the cytosol, whereas bound ribosomes produce proteins that are inserted into the ER.

Ribosomes

Free-make proteins that are in use in the cytoplasm, synthesis proteins also, translate mRNA into primary sequence protein Bound- make proteins for plasma membrane, to be secreted out of the cell or for packaging within lysosomes, bound to ER, synthesize proteins for export. (digestion of bacteria). Translate mRNA into proteins that are transported outside the cell.

Provide a mechanism to explain how the mRNA from one species can be used to make proteins in a different species. part 4

Universal process of protein synthesis.

Anabolism

Use the energy stored in ATP to build new molecules.

Contractile Vacuoles

Used to pump excess water from plant cells (aka homeostasis) by osmosis

Peptide hormone

Water-soluble and have a receptor in the plasma membrane. Because peptide hormones are polar, their receptors must be on the extracellular side of the plasma membrane.

Cell Membrane

the cell membrane separates the cell from its external environment, and is selectively permeable (controls what gets in and out). It protects the cell and provides stability. Proteins are found embedded within the plasma membrane, with some extending all the way through in order to transport materials. Carbohydrates are attached to proteins and lipids on the outer lipid layer.

temp

higher = increase in fluidity lower = decrease in fluidity

cholesterol

increase of fluidity @ low temp decrease of fluidity @ high temp (increase of intermolecular forces)

Cytoplasmic side

inside the cell

Membrane Carbohydrates

interact with the surface molecules of other cells, facilitating cell-cell recognition - short oligosaccharides covalently bound (inside golgi/RER) to proteins (glycoproteins) or lipids (glycolipids) interact with molecules on the outside of the cell.

Fluidity

is important in making and breaking membranes (endo/exocytosis) hydrophilic/phobic restrict entries/exits of substances phospholipids and cholesterol contribute to membrane fluidity

Unsat region

kinky part of lipid

Macrophages are cells of the immune system that engulf and destroy bacteria via intracellular digestion in their abundant what organelle does this?

lysosomes

Effect of saturation, cholesterol and protein content on membrane fluidity and permeability

- cholesterol - "buffer", preventing lower temp from inhibiting fluidity and preventing higher temp. from increasing fluidity < more fluid, more permeable/leaky - protein content - diffusion is slower due to crowding, mobile in the lipid fluid environment, low fluidity

Ion Channel

- flow of ions can occur through an ion channel ion channel proteins - help maintain an electrochem gradient across a cell membrane - open in response to a stimulus to allow ion flow - closes to allow electrochem gradient to reform - active transport makes gradient - pushes protons out makes ion gradient - active transport restores channels

Influence bilayer fluidity

- length of acid tails * lonq = more interactions and less fluidity

passive transport

- molecules move down a concentration gradient - No ATP required - Uses gradient to move - Moves stuff in and out - Communicates - passive, o energy to occur

Voltage gated ion channels

- opens in response to a change in charge across the membrane - common in neurons, muscle cells - ions in - another voltage change - gates closed (no ions flow across membrane) - gate open (ions flow through membrane)

Mechanical gated ion channels (sound, wind wave)

- opens in response to a physical stimulus - sound waves bend small projections in ear cells which open ion channels

Light gated ion channels

- sensitive to visible wavelengths of light - charged or water - 400-700 nm

Ligand gated ion channels

- small signaling molecule - ligand itself not transported, but triggers ion channels to open - binds and opens ion channels - physical - positive ions flow in changing voltage across membrane

Simple diffusion (passives)

- transport of small nonpolar molecules across the membrane - No specialized transport proteins - O2 always coming into cells - CO2 always coming out of cell (both above are non-membrane transports) - Ethanal - Steroids (both above free range to cells) - Fatty acids - NO (nitric oxide) DO NOT REQUIRE ANY KIND OF PROTEINS - cellular respiration - squeeze between phospholipids (good)

Functions of Plasma Membrane

1). Isolate the cytoplasm from the external environment. 2). Regulating the transport of molecules into/out of the cell. 3). Cell recognition/communication

Cell theories

1. Cells are the most basic fundamental units of life that can do all the functions of life. 2. All organisms are composed of cells 3. All cells come from pre-existing cells - cell division in bacteria: Binary Fusion (prokaryote)

Evolving life

1. Formation of small molecules containing carbon and hydrogen 2. Formation of self-replicating info. containing molecules - the nucleic acid RNA can both carry info. and catalyze the reaction necessary for replication 3. Development of membrane - membranes that compartmentalize the self-replicating molecules form their surroundings facilitated metabolic activity

Plasma membrane functions

1. Isolate cytoplasm from external environment and containment of cellular contents 2. Transport of molecules into/out of the cell 3. Cell recognition/communication

Cytoplasm

A jellylike fluid inside the cell, that is separated from the environment by plasma membrane Makes up most of the cell and constantly streaming

Signal

A molecule that triggers a cellular response.

Animal Cell

A small living part of a multicellular organism that eats to gain energy and reproduces sexually.

Plant Cell

A small living part of a multicellular organism that makes its own food in chloroplast and reproduces sexually or asexually.

Describe and draw the chemical structure of membranes and explain the nature of their fluidity.

A. a double layer of lipid / phospholipid molecules with head and tails; B. hydrophilic / phosphate / polar heads and hydrophobic / hydrocarbon / fatty acid / non-polar tails labelled; C. integral protein - passing completely through the lipid bilayer; D. peripheral protein - shown on the surface and not penetrating the lipid bilayer; E. glycoprotein with carbohydrate attached on outside; F. cholesterol shown embedded in bilayer; G. thickness indicated (10 ( +/- 3) nm);

List the functions of membrane proteins

A. hormone binding sites; B. enzymes; C. electron carriers; D. channels for (passive) transport; E. (pumps) for active transport; F. cell to cell recognition; G. receptors for neurotransmitters;

Explain how the hydrophobic and hydrophilic properties of phospholipids help to maintain the structure and permeability of cell membranes.

A. hydrophobic tail / hydrophilic head; B. head made from glycerol and phosphate; C. tail made from two fatty acids; D. saturated / unsaturated fatty acid (in tail); E. phospholipids form a bilayer; F. stability to membrane brought about by attraction between hydrophobic tails / between hydrophilic heads and water; G. phospholipid bilayer forms with heads in contact with water on both sides of membrane / with environment and cytoplasm; H. hydrophobic tails found in center (of bilayer) away from water; I. phospholipids allow for membrane fluidity / flexibility; J. fluidity / flexibility helps membranes to be (functionally) stable; K.phospholipids with short fatty acids / unsaturated fatty acids are more fluid; L. fluidity is important in breaking and remaking membranes (eg endocytosis / exocytosis); M. phospholipids can move about / move horizontally / "flip flop" to increase fluidity; N. hydrophilic / hydrophobic layers restrict entry / exit of substances;

Golgi disorders result in a malfunction of the secretory pathways, which package and secrete proteins synthesized in the rough endoplasmic reticulum I-cell disease is caused by a failure of the Golgi body to properly phosphorylate and sort proteins, resulting in secretion of some proteins that would otherwise be destined for lysosomes. What might be a result of I-cell disease?

Accumulation of molecules that cannot be broken down in lysosomes.

Differential Gene Expression

All cells have the exact same genetic material, but just express different genes for different functions. For example, the cells in your eyes have the genetic information as the cells in your nose but don't express those genes because expressing olfactory genes in your eyes would not be beneficial.

DNA

All living cells use deoxyribonucleic acid as the molecular basis of genetic info., which is organized into chromosomes. DNA (transcribe) > RNA (translate) > Proteins

Excocytosis

An active transport process in which large particles, such as wastes, leave the cell - movement of large particles in/out of the cell - secretory vesicle

Response

Any change that occurs in the cell after a signal binds to a receptor on the plasma membrane. Some examples of a response are: ◦Change in membrane potential ◦Change in gene expression ◦Change in metabolism

State the name of the protein coded for by the mRNA. part 1

Aquaporin channel protein

lipid rafts

Collections of similar lipids with or without associated proteins that serve as attachment points and cholesterol - Lipid raft keeps the proteins together so things function properly.

phylogenetic tree

COMMON ANCESTOR - Bacteria - prokary (endosymbiosis of aerobic heterotrophic prokaryotes) - Archaea (mitochondria) - prokary - Plants (chloroplast) - eukary - Animals - eukary

why the mitochondria and chloroplast are not part of the endomembrane system

Chloroplasts and mitochondria do not produce proteins destined for secretion or insertion into the plasma membrane. They are energy transfer organelles with endosymbiotic origins. They do not contribute to the generation of the membrane.

False

Cyanobacteria (photosynthetic prokaryotes) have chloroplasts.

Sodium potassium pump

EXTRACELLULAR - High Na+ concentration - Low K+ concentration outside of cell CYTOPLASM - High K+ concentration - Low Na+ concentration inside cell

How would a change in protein synthesis influence the body?

Errors in protein synthesis disrupt cellular fitness, cause disease phenotypes, and shape gene and genome evolution.

Hypotonic

Having a lower concentration of solute Therefore, water will move away from the hypotonic species and the species will shrivel. - Cells animal - hypertonic (burst)

Nucleus

Houses chromatin, site of RNA synthesis, dual membrane structure with protein-rich nuclear pore complexes that regulate passage into/out of the nucleus.

Endosymbiosis

Is a relationship between 2 species in which one organism lives inside the cell or cells of other organisms (the host). Both benefit and internal bacteria are passed on from generation to generation "endo" - inside (of mitochondria) In-folding of outer membrane forms membrane-bound compartments. Free-living cells (such as mitochondria/chloroplasts) were able to be ingested by other free-living cells. Current day mitochondria and chloroplasts "fit" into the membrane-bound compartments. - IN EUKARYA

Vacuoles

Large vesicles derived from the ER and Golgi. Diverse types include food vacuoles, contractile vacuoles, central vacuoles in plants. Store material such as water, food, sugar , minerals, and waste product.

Steroid hormones

Lipid-soluble (made from cholesterol) and have receptors inside the cell nucleus. When steroid hormones bind to a receptor, it is the hormone-receptor complex that binds to DNA in the nucleus to cause a response.

Glycolipids

Membrane carbohydrates are covalently bonded to lipids. (function- cells ability to distinguish one type of neighboring cell from another)

Glycoproteins

Membrane carbohydrates are covalently bonded to proteins. (function- cells ability to distinguish one type of neighboring cell from another)

Peripheral

Not integrated in the bilayer. Peripheral proteins are temporarily attached to integral or transmembrane proteins. Peripheral proteins have varied functions.

Endomembrane system

Nuclear envelope, RER, SER, vesicles and vacuoles, golgi, lysosomes, plasma membrane

Which of the following organelles are involved in the synthesis of a secreted protein ? part 5

Nucleus, RER, Golgi, Vesicles, Plasma Membrane

intergral

Only associated with one side of the plasma membrane. Partially or wholly embedded in the bilayer. Integral proteins have a variety of functions.

Plants and Animals

PLANTS - Cell wall - Large vacuole - Chloroplasts - Flagella only in gametes - Rectangle shape ANIMALS - Small or no vacuole - No chloroplast - Flagella/cilia - Irregular circle SIMILARITIES - Mitochondrion - Golgi app. - RER & SER - Nucleus - Cytoplasm - Ribosomes

Transmembrane

Proteins that extend all the way through the bilayer. Transmembrane proteins usually serve as channels which allow molecules to come into the cell.

The cells of the pancreas are specialized to produce secreted proteins and have a lot

RER

Functions of cells

RMH GR Reproduction, Metabolism, Growth, Response, Homeostasis

Photosynthesis

Remember that photosynthesis evolved before cellular respiration. One of the products of photosynthesis (oxygen) is the main reactant of cellular respiration.

Cytoplasm

Ribosome clamps onto a strand of mRNA, building a new protein.

The cells of the ovaries and testes are specialized to produce steroid hormones and have a lot of

SER

Paracrine

Signals diffuse from one cell and influence other nearby cells.

Endocrine

Signals travel long distances throughout the body to produce a response.

Mitochondria

Site of cellular respiration. Dual membrane structure. Contain DNA, RNA, and ribosomes. Highly folds. Releases food energy for the cells. Powerhouse of the cell.

SER

Site of lipid synthesis including sex hormones, detox of drugs and poisons, storage of calcium ions.

Chloroplast

Site of photosynthesis. Dual membrane (almost triple) structure. Contains DNA, RNA, and ribosomes.

Ribosomes

Site of protein synthesis Proteins made in free ribosomes stay inside the cell

RER

Site of translation of bound ribosomes peptides is directed to Golgi in vesicles upon leaving RER. It is continuous with the nuclear membrane and with the SER. Site of membrane synthesis. Proteins made here are bound to leave. Protein synthesis.

Vesicles

Small membrane poches that move around the cell and deliver molecules to organelles or to be secreted from the cell.

Golgi

Specializes in protein modification and vesicle delivery to the plasma membrane cis and trans sidedness.

Catalyze

Speeds up chemical reaction by lowering the activation energy

Homeostasis

The ability of the body to maintain relatively stable internal conditions even though the outside world changes. internal environment = fluid that surrounds the cells

Cytoskeleton

The network of fibers that organizational structure and activities in the cell. Microtubules, microfilaments, and intermediate filaments. Conduct for movement of motor proteins. The framework, tracks (transport) protein.

Autocrine

The cell that produces the signal also responds to that signal.

Where does the mRNA come from part 2

The mRNA is extracted from cells into which water diffuses at a high rate.

Directional

The plasma membrane is directional, meaning that the interior and exterior of the cells have different chemical structure that allows them to regulate cell function and stabilize the cell.

Cytoskeleton

Throughout the cell, shape, support, facilitate movement through 3 main components. - Microfilaments, intermediate filaments, & microtubules

Why Is it important that the oocytes used in this investigation do not normally synthesize aquaporins? part 3

To demonstrate that the inserted mRNA codes for the aquaporin channel expressed in the plasma membrane. To demonstrate that mRNAs can be transferred between species. To demonstrate that the aquaporin is responsible for the high rate of osmosis.

transmembrane proteins

Transmembrane proteins are integral proteins that do not extend all the way through the membrane. (no carbohydrates attached)

Water

Transport occurs through channel proteins known as aquaporins.

Glyco

carbs

Similarities between prokaryotes and eukaryotes

cell membrane, ribosomes, DNA, cytoplasm

Extracellular side (communication)

outside the cell where carbohydrates attach

Endocytosis

process by which a cell takes material into the cell by infolding of the cell membrane - movement of large particles in/out of the cell - came from golgi app -endocytotic vesicle

degree of sat

sat straight = decrease in fluidity unsat kinky & more distance = increase in fluidity

Which of the following is NOT a membrane-enclosed organelle?

ribosome

Immature proteins that are transported in vesicles are synthesized by

ribosomes on the rough endoplasmic reticulum.

All cells are...

surrounded by a biological membrane - 2 layers of lipid molecules (lipid bilayer) - membrane-associated proteins and carbohydrate molecules

The membrane surrounding each organelle in the endomembrane system

two are true statements

Hypertonic

when comparing two solutions, the solution with the greater concentration of solutes water will move toward the hypertonic species and the species will lyse (pop). Water will always move towards higher concentration - Cells animal - shriveled (hypotonic)

Isotonic

when the concentration of two solutions is the same Equal net movement - Cells animal - normal

Chloroplast

which allows them to photosynthesize/perform photosynthesis. (close to the surface of a plant leaf)