Bio Cells and Transport

Réussis tes devoirs et examens dès maintenant avec Quizwiz!

centrioles

Cell organelle that aids in cell division in animal cells only a minute cylindrical organelle near the nucleus in animal cells, occurring in pairs and involved in the development of spindle fibers in cell division. key part of cell division - composed of tubulin

Eukaryotes

Cells that contain nuclei, membrane bound organelles organized dna one or more chromosomes single or multi cells

Secretory Protein

Released from a cell after being made in the ER shipped to the golgi and then packaged in a vessicle A secretory protein is any protein, whether it be endocrine or exocrine, which is secreted by a cell. Secretory proteins include many hormones, enzymes, toxins, and antimicrobial peptides. Secretory proteins are synthesized in the endoplasmic reticulum

Rough ER

Rough ER makes additional membrane for itself and proteins destined for secretion Once proteins are synthesized, they are transported in vesicles to other parts of the endomembrane system

glycoprotein

helps cells to communicate and send signals so they know if another cell needs something — like if they need to produce more skin cells. cell-cell recognition enables cells of the immune system to recognize and reject foreign cells, such as infectious bacteria

Identify the limiting factor in cell size

if cells are too large, it takes too long for waste to defuse out of cells, so the waste could poison the cell it takes too long for nutrients to travel in the cell so it could starve competition, predation and herbivory, parasitism and disease, stress from overcrowding

Describe the role the cell membrane plays in allowing substances into and out of a cell

selectively permeable ll cells are enclosed with a cell membrane. A selectively permeable cell membrane is one that allows certain molecules or ions to pass through it by means of active or passive transport. it decides what goes in and out

Oxygen on the Earth

- cyanobacteria comes to Earth, separates H2 from H2O, leaving behind toxic O2 - peroxisomes detoxifies - eventually, eukaryotes finally adapt to an oxygen environment

Explain the role of the endomembrane system in the functioning of a cell

-It separates the contents of the cell from its outside environment and it regulates what enters and exits the cell 1. synthesis of proteins and transports into membranes, organelles, or out of cells. 2. Metabolism and movement of lipids 3. Detoxification of poisons. Nuclear Envelope, Plasma Membrane, Endoplasmic Reticulum, Golgi Apparatus, Lysosomes, and Vacuoles

Endoplasmic Reticulum

A cell structure that forms a maze of passageways in which proteins and other materials are carried from one part of the cell to another. A system of membranes that is found in a cell's cytoplasm and that assists in the production, processing, and transport of proteins and in the production of lipids. a network of membranous tubules within the cytoplasm of a eukaryotic cell, continuous with the nuclear membrane. It usually has ribosomes attached and is involved in protein and lipid synthesis. rough ER has ribosome covered surface while smooth ER doesnt Active in membrane synthesis and mataboloic process

Nucleoid

A dense region of DNA in a prokaryotic cell. Nuclear region in prokaryotes Condensed DNA of the cell

Concentration Gradient

A difference in the concentration of a substance across a distance. difference in concentration of a substance on two sides of a membrane

Phospholipid Bilayer

A double layer of phospholipids that makes up plasma and organelle membranes. Plasma membrane layers composed of phospholipid molecules arranged with polar heads (hydrophilic) facing the outside and nonpolar tails (hydrophobic) facing the inside. A two-layer "sandwich" of molecules that surrounds an organelle or cell is called

Microtubules

A hollow rod composed of tubulin proteins that makes up part of the cytoskeleton in all eukaryotic cells and is found in cilia and flagella. Thick hollow tubes that make up the cilia, flagella, and spindle fibers. A hollow rod of the protein tubulin in the cytoplasm of all eukaryote cells that make up cilia, flagella, spindle fibers, and other cytoskeletal structures of cells Microtubules are the largest type of filament, with a diameter of about 25 nanometers (nm), and they are composed of a protein called tubulin. Actin filaments are the smallest type, with a diameter of only about 6 nm, and they are made of a protein called actin.

Cytoplasm

A jellylike fluid inside the cell in which the organelles are suspended Gel-like fluid where the organelles are found Described as the cytosol, largely composed of water.

Central Vacuole

A membranous sac in a mature plant cell with diverse roles in reproduction, growth, and development. A large vacuole that rests at the center of most plant cells and is filled with a solution that contains a high concentration of solutes The central vacuole is a cellular organelle found in plant cells. It is often the largest organelle in the cell. It is surrounded by a membrane and functions to hold materials and wastes. It also functions to maintain the proper pressure within the plant cells to provide structure and support for the growing plant. Many plant cells have a large, single central vacuole that typically takes up most of the room in the cell (80 percent or more). Vacuoles in animal cells, however, tend to be much smaller, and are more commonly used to temporarily store materials or to transport substances.

Endomembrane System

A network of membranes inside and around a eukaryotic cell, related either through direct physical contact or by the transfer of membranous vesicles. The endomembrane system is composed of the different membranes that are suspended in the cytoplasm within a eukaryotic cell. These membranes divide the cell into functional and structural compartments, or organelles. The collection of membranes inside and around a eukaryotic cell, related either through direct physical contact or by the transfer of membranous vesicles; includes the smooth and rough endoplasmic reticulum, the Golgi apparatus, lysosomes, and vacuoles. In general, the endomembrane system regulates protein traffic and performs metabolic functions in the cell. It accounts for more than half the total membrane in many eukaryotic cells. Some components of the endomembrane system are able to communicate with others and transfer small membrane segments called vesicles Allows for the synthesis, storage, and export of molecules

prokaryotic vs eukaryotic cells

Both prokaryotic and eukaryotic cells have a plasma membrane and one or more chromosomes and ribosomes Eukaryotic cells have a membrane-bound nucleus and a number of other organelles, whereas prokaryotes have a nucleoid and no true organelles

Glycoprotein

A protein with one or more carbohydrates covalently attached to it. A protein with one or more covalently attached carbohydrates. short sugar chains attached to proteins

Cell wall

A rigid layer of nonliving material that surrounds the cells of plants and some other organisms. A rigid structure that surrounds the cell membrane and provides support to the cell

Signal Transduction

A series of molecular changes that converts a signal on a target cell's surface to a specific response inside the cell. Signal transduction (also known as cell signaling) is the transmission of molecular signals from a cell's exterior to its interior. Signals received by cells must be transmitted effectively into the cell to ensure an appropriate response. This step is initiated by cell-surface receptors. the linkage of a mechanical, chemical, or electromagnetic stimulus to a specific cellular response The intracellular process triggered by the binding of a ligand to its receptor on the cell surface. Typically this activates seond messenger pathways.

Capsule

A sticky layer that surrounds the cell walls of some bacteria, protecting the cell surface and sometimes helping to glue the cell to surfaces. Covers the cell wall in prokaryotes. What anatomical feature is a thin, semipermeable membrane that envelopes the entire lens.

Plasma Membrane

A thin, phospholipid and protein molecule bilayer that encapsulates a cell and controls the movement of materials in and out of the cell through active or passive transport. The membrane at the boundary of every cell that acts as a selective barrier, thereby regulating the cell's chemical composition. A selectively-permeable phospholipid bilayer forming the boundary of the cells the organelle that controls what enters and leaves the cell

Organelles

A tiny cell structure that carries out a specific function within the cell. A membrane-enclosed structure with a specialized function within a cell.

What enables eukaryotes to perform more specialized functions than prokaryotes?

A well- developed cytoskeleton Their complex organization, eukaryotic cells can carry out more specialized functions than prokaryotes cells can. nucleus Membrane bound organelles

Chloroplast

An organelle found in plant and algae cells where photosynthesis occurs (in green plant cells) a plastid that contains chlorophyll and in which photosynthesis takes place. Photosynthetic organelle; converts energy of sunlight to chemical energy stored in sugar molecules (not in animal cells) contains chlorophyll which is why it is green

Leeuwenhoek

Antoni van Leeuwenhoek later described cells that could moveHe viewed bacteria with his own hand-crafted microscopes It was he who discovered bacteria, free-living and parasitic microscopic protists, sperm cells, blood cells, microscopic nematodes and rotifers, and much more. His researches, which were widely circulated, opened up an entire world of microscopic life to the awareness of scientists. Who discovered organisms in a pond? 1670's ; father of modern microbiology; first to observe living cells Discovery of bacteriaAntonie Philips van Leeuwenhoek[note 1] (/ˈleɪvənhʊk/, Dutch: [ɑnˈtoːni vɑn ˈleːuə(n)ˌɦuk] ( listen); 24 October 1632 - 26 August 1723) was a Dutch tradesman and scientist. He is commonly known as "the Father of Microbiology", and considered to be the first microbiologist. He is best known for his work on the improvement of the microscope and for his contributions towards the establishment of microbiology. Using his handcrafted microscopes, he was the first to observe and describe microorganisms, which he originally referred to as animalcules (from Latin animalculum = "tiny animal"). Most of the "animalcules" are now referred to as unicellular organisms, though he observed multicellular organisms in pond water. He was also the first to document microscopic observations of muscle fibers, bacteria, spermatozoa, and blood flow in capillaries. Van Leeuwenhoek did not write any books; his discoveries came to light through correspondence with the Royal Society, which published his letters.

Pili

Appendages that allow bacteria to attach to each other and to transfer DNA Cytoplasmic bridges the connect one cell to another and that allow DNA to move from one cell to another in a form of primitive sexual reproduction called conjugation

Cell

Basic unit of life

Phagocytosis

Cell eating A type of endocytosis in which a cell engulfs large particles or whole cells Cellular process of engulfing food and encapsulating it in a vacuole.

peroxisomes

Contain oxidase enzymes that detoxify alcohol, hydrogen peroxide, and other harmful chemicals Organelles in both plants and animals that break down peroxide, a toxic byproduct of cell respiration. - contain enzymes involved in metabolic reaction - synthesis of lipids (cholesterol) - detoxified O2 by converting to H2O (during the prokaryotic evolution to eukaryotic)

Ribosome

Cytoplasmic organelles at which proteins are synthesized. a minute particle consisting of RNA and associated proteins, found in large numbers in the cytoplasm of living cells. They bind messenger RNA and transfer RNA to synthesize polypeptides and proteins. A cell organelle constructed in the nucleolus and functioning as the site of protein synthesis in the cytoplasm; consists of rRNA and protein molecules, which make up two subunits. Ribosomes are involved in the cell's protein synthesis Ribosomes are synthesized in the nucleolus, which is found in the nucleus Cells that must synthesize large amounts of protein have a large number of ribosomes Some ribosomes are free ribosomes; others are bound Free ribosomes are suspended in the cytoplasm Bound ribosomes are attached to the endoplasmic reticulum (ER) associated with the nuclear envelope

Anchoring Junctions

Functions like rivets fastening cells into strong sheets — filaments made from karitin — reinforce these junctions connect adjacent cells when cadherins in the plasma membrane connect to intermediate filaments provide strong adhesion between cells fasten cells together into sheets animal skin/heart muscles — they hold cells together but can still move — important for skin which is always moving and the heart which is also always moving so that they can stretch but stay as one desmosomes

Microfilaments

Long, thin fibers that function in the movement and support of the cell Solid rods od the protein actin that make up part of the cytoskeleton a small rodlike structure, about 4-7 nanometers in diameter, present in numbers in the cytoplasm of many eukaryotic cells.

Nucleolus

Makes ribosomes A specialized structure in the nucleus, formed from various chromosomes and active in the synthesis of ribosomes Found inside the nucleus and produces ribosomes

4 processes in eukaryotic cells

Manufacturing (the nucleus, ribosomes, endoplasmic reticulum, and Golgi apparatus) Breakdown of molecules (lysosomes and vacuoles) Energy processing Structural support, movement, and communication

Tight Junctions

Seal adjacent epithelial cells in a narrow band just beneath their apical surface — they limit the passage of molecules and ions through the space between cells Seals two adjacent cells so materials won't leak out of cells animal digestive track linings inside animal body. prevent leakage. Tight junctions are prominent in cheek cells so leakage out of the mouth is prevented

Vesicles

Small vacuoles small membrane sacs that specialize in moving products into, out of, and within a cell a fluid- or air-filled cavity or sac, in particular. When a cell needs to move a molecule many times, it uses vesicles. Vesicles are cellular organelles that are composed of a lipid bilayer. You can think of vesicles as cellular envelopes that are used to transport materials from one place to another. Vesicles also function in metabolism and enzyme storage as well.

smooth ER

Smooth ER is involved in a variety of diverse metabolic processes Enzymes produced by the smooth ER are involved in the synthesis of lipids, phospholipids, and steroids Processes include metabolism of carbohydrates and detoxification of drugs and poisons What organ has a lot of SER?

Tonicity (Hyper, Hypo, Iso)

The ability of a solution to cause a cell to gain or lose water; depends partly on concentration of nonpenetrating solutes relative to inside of cell. A hypertonic solution has a greater concentration of solutes than another solution. In biology, the tonicity of a solution usually refers to its solute concentration relative to that of another solution on the opposite side of a cell membrane; a solution outside of a cell is called hypertonic if it has a greater concentration of solutes than the cytosol inside the cell. When a cell is immersed in a hypertonic solution, osmotic pressure tends to force water to flow out of the cell in order to balance the concentrations of the solutes on either side of the cell membrane. The cytosol is conversely categorized as hypotonic, opposite of the outer solution. A hypotonic solution has a lower concentration of solutes than another solution. In biology, a solution outside of a cell is called hypotonic if it has a lower concentration of solutes relative to the cytosol. Due to osmotic pressure, water diffuses into the cell, and the cell often appears turgid, or bloated. For cells without a cell wall such as animal cells, if the gradient is large enough, the uptake of excess water can produce enough pressure to induce cytolysis, or rupturing of the cell. A solution is said to be isotonic when its effective osmole concentration is the same as that of another solution. In biology, the solutions on either side of a cell membrane are isotonic if the concentration of solutes outside the cell is equal to the concentration of solutes inside the cell. In this case the cell neither swells nor shrinks because there is no concentration gradient to induce the diffusion of large amounts of water across the cell membrane. Water molecules freely diffuse through the plasma membrane in both directions, and as the rate of water diffusion is the same in each direction, the cell will neither gain nor lose water.

How does the cell membrane help a cell maintain homeostasis?

The cell membrane is a biological membrane that separates the interior of all cells from the outside environment. The cell membrane is selectively permeable to ions and organic molecules and controls the movement of substances in and out of cells. The basic function of the cell membrane is to protect the cell from its surroundings. It consists of the phospholipid bilayer with embedded proteins. Cell membranes are also involved in a variety of cellular processes. The cell membrane is present to control the passage of molecules in/out of the cell. It allows the cell to have a different ionic concentration from the extraceullular (outside) environment. It maintains the desired environment of the cell which allows correct processing and packaging inside the cell. Inside the cell there is a high concentration of K ions and low Na. This allows the cell to have an overall internal negative eletrochmeical gradient (aided by the NaK Pump) which is vital to many processes inside the cell. Without the membrane the cell could not control what is moving into and out of it and hence could not maintain a steady state.

Peripheral Proteins

The proteins of a membrane that are not embedded in the lipid bilayer; they are appendages loosely bound to the surface of the membrane. Protein appendages loosely bound to the surface of the membrane and not embedded in the lipid bilayer. are not embedded in the lipid bilayer at all. Instead, the are loosely bound to the surface of the protein, often connected to integral proteins Peripheral membrane proteins are membrane proteins that adhere only temporarily to the biological membrane with which they are associated. These proteins attach to integral membrane proteins, or penetrate the peripheral regions of the lipid bilayer.

How did eukaryotes evolve from prokaryotes?

There is an idea that parts of organelles, such as mitochondria and plastids, originate from prokaryotic bacteria; these organelles still contain a vestigial genetic system. Then another prokaryote engulfed these organelles through endosymbiosis and they became apart of the cell as a mutual assistant, instead of being broken down. Cells that are capable of engulfing other cells are called phagocytes, which have a flexible membrane, which can fold around their smaller prey, trapping the prey inside the cell. As these phagocytes engulfed these organelles, these organelles must have increased their rate of production and survival so that through natural selection, these organelles would be passed on. Plastids evolved from cyanobacteria, photosynthetic cells responsible for the oxygen crisis; consequently, plastids are associated with chloroplasts, which undergo photosynthesis in a plant cell.

Intermediate filaments

Threadlike proteins in the cell's cytoskeleton that are roughly twice as thick as microfilaments Cytoskeletal filaments with a diameter in between that of the microtubule and the microfilament. Intermediate filaments are composed of many different proteins and tend to play structural roles in cells. intermediate filaments are one of three types of cytoskeletal elements. The other two are thin filaments (actin) and microtubules. Frequently the three components work together to enhance both structural integrity, cell shape, and cell and organelle motility.

Gap Junctions

What is the name of hydrophilic pores that allow the direct passage of ions and particles between two adjacent cells? Points that provide cytoplasmic channels from one cell to another with special membrane proteins. Also called communicating junctions. animal heart muscles, coordinate contractions Allow for exchange of ions, second messengers and small-metabolites between adjacent cells and are formed by two unrelated protein families provide cytoplasmic channels between adjacent animal cells. heart cells use this junction because they need to communicate so they can all beat at same rate. Neurons also need to communicate fast so they use these junctions,

Transport vesicle

a vesicle that moves from one part of the cell to another A tiny membranous sac in a cell's cytoplasm carrying molecules produced by the cell. Vesicles in transit from one part of the cell to another. Transport vesicles can move molecules between locations inside the cell, e.g., proteins from the rough endoplasmic reticulum to the Golgi apparatus. Membrane-bound and secreted proteins are made on ribosomes found in the rough endoplasmic reticulum.

The Cell Theory

all living things are composed of cells all cells come from other cells not established till we had microscopes

Cilia

cilia and flagella move liquid past the surface of the cell Hairlike projections that extend from the plasma membrane and are used for locomotion A hair-like structure on teh cell surface composed of microtubules ina '9+2' arrangement (nine pairs of microtubles surrounding 2 single microtubules in the center). Teh microtubules are conneted with a contractile protien called dynein. Cilia beat in a repetitive sweeping motion, which helps to move substances along the surface of the cell. They are particularly important in the respiratory system, where they sweep mucus out of the trachea and up to the mouth and nose. Hair-like projections on the cell surface used for locamotion or the movement of fluid over a cell. While some protists have flagella and cilia that are important in locomotion, some cells of multicellular organisms have them for different reasons Cells that sweep mucus out of our lungs have cilia Animal sperm are flagellated. A flagellum propels a cell by an undulating, whiplike motion Cilia, however, work more like the oars of a crew boat

Lysosome

digestive organelle where macromolecules are hydrolyzed (add water to break them down) not it plant cells In an ANIMAL CELL. Contain chemicals that break down certain materials. Breaks down dead cells. A small, round cell structure containing chemicals that break down large food particles into smaller ones. A lysosome is a membranous sac containing digestive enzymes The enzymes and membrane are produced by the ER and transferred to the Golgi apparatus for processing The membrane serves to safely isolate these potent enzymes from the rest of the cell. One of the several functions of lysosomes is to remove or recycle damaged parts of a cell The damaged organelle is first enclosed in a membrane vesicle Then a lysosome fuses with the vesicle, dismantling its contents and breaking down the damaged organelle

Hooke

first described and named a cwll he observed microscopic chambers in plants that reminded him of monk cells so he called them cells

Vacuoles

it's mostly in plants but animal cells do have much smaller less useful/prominent vacoules prominent organelle in older plant cells functions include storage, breakdown of waste products, enlargement of vacuole is a major mechanism of plant growth Storage Many plant cells have a large, single central vacuole that typically takes up most of the room in the cell (80 percent or more). Vacuoles in animal cells, however, tend to be much smaller, and are more commonly used to temporarily store materials or to transport substances. central vacuole in plants that stores water (and has functions like a lysosome) pigment vacuoles in plants to provide color to flowers contractile vacuoles in some protists to expel water from the cell

Flagella

locomotion organelle present in some animal cells — composed of microtubules they rotate the cell A long cellular appendage specialized for locomotion, formed from a core of nine outer doublet microtubules and two inner single microtubules, ensheathed in an extension of plasma membrane. Both flagella and cilia are made of microtubules wrapped in an extension of the plasma membrane A ring of nine microtubule doublets surrounds a central pair of microtubules This arrangement is called the 9 + 2 pattern and is anchored in a basal body with nine microtubule triplets arranged in a ring

Cytoskeleton

microfilaments, intermediate filaments, microtubules Reinforces cell's shape, functions in cell movement; components are made of protein A network of fibers that holds the cell together, helps the cell to keep its shape, and aids in movement The cytoskeleton is composed of three kinds of fibers Microfilaments (actin filaments) support the cell's shape and are involved in motility (thin) Intermediate filaments reinforce cell shape and anchor organelles Microtubules (made of tubulin) shape the cell and act as tracks for motor protein (thickest)

Prokaryotes

no membrane bound organelles including nucleus smaller dna not that organized only single celled only one chromosome few organelle Cells that do not contain nuclei

Golgi Apparatus

organelle active in synthesis, sorting and secretion of cell product An organelle found in eukaryotic cells responsible for the final stages of processing proteins for release by the cell. An organelle in eukaryotic cells consisting of stacks of flat membranous sacs that modify, store, and route products of the endoplasmic reticulum.

Mitochondria

organelle where cellular respiration occurs most ATP is generated here which provides energy for the cell to move, divide, etc. An organelle found in large numbers in most cells, in which the biochemical processes of respiration and energy production occur. Enclosed by two membranes with the inner membrane folded; contains its own DNA (used to be a prokaryotic cell) powerhouse of cell

Compare and contrast animal versus plant cells

plants: chloroplasts, more prominent vacuoles, cell walls, different junctions, plasmodesmata animals: lysosomes, flagella, centrioles

Integral Proteins

proteins implanted within lipid bilayer of plasma membrane Typically transmembrane proteins with hydrophobic regions that completely span the hydrophobic interior of the membrane. An integral membrane protein (IMP) is a type of membrane protein that is permanently attached to the biological membrane. All transmembrane proteins are IMPs, but not all IMPs are transmembrane proteins. IMPs comprise a significant fraction of the proteins encoded in an organism's genome.

fluid mosaic model

the cell membrane acts more like a liquid then a solid because it is made out of unsaturated fat in the polypeptides so the tails have kinks so they cannot easily stack and form a solid like saturated fats. Colestral wedged between the tails also helps with the separation

Microscopy (TEM, SEM)

the use of the microscope Transmission electron microscopy (TEM) is a microscopy technique in which a beam of electrons is transmitted through an ultra-thin specimen, interacting with the specimen as it passes through. Scanning Electron Microscopy. A scanning electron microscope (SEM) scans a focused electron beam over a surface to create an image. The electrons in the beam interact with the sample, producing various signals that can be used to obtain information about the surface topography and composition.

Plasmodesmata

water and small solutes van pass from cell to cell a channel that allows molecules and substances to move back and forth as needed — communication plant

extracellular matrix

whats on the outside of a cell mostly just animal cells because only water surrounds plant cells calcium surrounds a bone cell unique according to cell type

Nucleus (chromatin, chromosomes, nuclear envelope)

where DNA is located The nucleus is an organelle found in eukaryotic cells. Inside its fully-enclosed nuclear membrane, it contains the majority of the cell's genetic material. This material is organized as DNA molecules, along with a variety of proteins, to form chromosomes. chromatic: the material of which the chromosomes of organisms other than bacteria (i.e., eukaryotes) are composed. It consists of protein, RNA, and DNA. Chromosomes: a threadlike structure of nucleic acids and protein found in the nucleus of most living cells, carrying genetic information in the form of genes. A nuclear membrane, also known as the nucleolemma or karyotheca, is the phospho lipid bilayer membrane which surrounds the genetic material and nucleolus in eukaryotic cells. The nuclear membrane consists of two lipid bilayers—the inner nuclear membrane, and the outer nuclear membrane. The nuclear envelope is a double membrane with pores that allow material to flow in and out of the nucleus It is attached to a network of cellular membranes called the endoplasmic reticulum Nucleoli: nonmembranuous organelle involved in production of ribosomes — a nucleus has one or more of these


Ensembles d'études connexes

Texas Pre-License- Real Estate Finance

View Set

Patho: Cardiovascular Disorders Quiz 7

View Set

Psychology Midterm Study Guide Chapter 4

View Set