Purdue BIO 110 - Exam 2

Prokaryotes

Bacteria (Eubacteria) and Archaea

Eukaryotes

animals, plants, fungi, protists

Eukaryotic Cell

Cell type that ranges from 10-100 micrometers, has a true nucleus.

Archea

type of prokaryotic cell known for survival in extreme conditions.

Bacteria

the dominant form of life on the planet in both biomass and diversity. A single clump of soil is estimated to house more of this life form than the number of humans that has ever lived. 40 trillion live on our bodies!

Prokaryotic cell

Cell type that ranges from .1-5.0 micrometers in diameter, has no nucleus.

Nucleoid

the DNA clump at the center of Prokaryotic cells

Cytoplasm

semi-solid gel that contains cell organelles.

Ribosomes

"Universal Organelle" responsible for protein synthesis in cells/mitochondria

Compartmentalization

A characteristic of eukaryotic cells in which many organelles separate the cell into different regions. Allows a cell to carry out specialized chemical reactions in different places.

Rough Endoplasmic Reticulum

An endomembrane system covered with ribosomes where many proteins for transport are assembled.

nuclear envelope

A double membrane that surrounds the nucleus in the cell. Nuclear pores control exchange between this and the cytoplasm.

Chromatin

Clusters of DNA, RNA, and proteins in the nucleus of a cell (DNA bound to proteins, otherwise known as histones)

nuclear pores

holes in the nuclear envelope that allow materials to pass in and out of the nucleus

Endoplasmic Reticulus Structure

Network of interconnected hollow tubules made from lipid bilayers with a hole in the middle known as the lumen. Continuous throughout cell.

Smooth Endoplasmic Reticulum

An endomembrane system where lipids, cholesterol, and steroids are known to be synthesized, and desaturation occurs. Houses no ribosomes.

Vesicle

A membrane bound sac that contains materials involved in transport of the cell.

Golgi apparatus

A series of lipid bilayers in the appearance of flattened sacks. The cis face of this organelle receives transport vesicles from the ER containing macromolecules in need of modification and exportation from the cell which then bud off into new vesicles from the trans face.

Exocytosis

Process by which a cell releases large amounts of material by vesicles joining to the membrane

Endocytosis

process by which a cell takes material into the cell by infolding of the cell membrane

Lysosomes

An organelle containing digestive enzymes that break down old organelles/vesicles and foreign bodies

Tuberculosis

a bacterial infectious disease that works by preventing lysosomes from taking in its cells for digestion.

Phagocytosis

A type of endocytosis in which a cell engulfs large particles or whole cells

Mitochondrial Structure

Double membrane. Outer membrane which covers the entire cell, and inner membrane that is heavily folded and covered in ribosomes.

cristae

mitochondrial inner membrane folds

Mitochondria

Golgi apparatus

Rough Endoplasmic Reticulum

Smooth Endoplasmic Reticulum

Vesicle

Mitochondria

Powerhouse of the cell, organelle that is the site of ATP (energy) production.

Chloroplast

An organelle found in plant and algae cells where photosynthesis occurs

Chloroplast

Chloroplast Structure

Double membrane covering the entrie organelle housing stacks of disk shaped structures called thylakoids.

Granum

stack of thylakoids

Stroma

fluid portion of the chloroplast; outside of the thylakoids

Plastids

Plant-specific organelles that contain pigments, and example of these are chloroplasts, leucoplasts, chromoplasts, and vacuoles.

Leucoplasts

Organelles that store starches, fats or oils

Chromoplasts

Organelles that contain pigments used in photosynthesis, only it is a yellow or orange pigment instead of green.

Vacuoles

Cell organelle that stores materials such as water, salts, proteins, and carbohydrates. More commonly found in plant cells.

central vacuole

Nucleolus

Nucleolus

Makes ribosomes, rRNA

Cytoskeleton

A network of fibers that holds the cell together, helps the cell to keep its shape, and aids in movement. Fibers can participate in support, transport, and even movement.

Nucleoplasm

Fluid inside the nucleus

nuclear lamina

A net-like array of protein filaments lining the inner surface of the nuclear envelope; it helps maintain the shape of the nucleus.

extracellular matrix

a collection of extracellular molecules secreted by cells that provides structural and biochemical support to the surrounding cells. They hold together cells in tissues such as connective tissue including cartilage and bone.

basal lamina

commonly found in kidneys, and helps to control which molecules to pass from bloodstream to urine.

plasma membrane

A selectively-permeable phospholipid bilayer forming the boundary of the cells

Red Blood Cell Experiment

Taking place in 1925, and was able to conclude that cell membranes were indeed a bilayer by flatteneding the entire membrane of a red blood cell into a monolayer and comparing it to the surface area of a normal cell, it was found to be twice as large as the surface area.

amhipathic

containing both hydrophobic and hydrophillic regions.

Integrins

membrane proteins that connect to the cytoskelleton and cellular membrane.

integral membrane proteins

proteins that embedded in the plasma membrane. They span the whole membrane and are essentially floating in the lipid bilayer.

peripheral membrane proteins

proteins associated with but not embedded within the plasma membrane (they sit on the membrane surface).

cell fusion experiments

Took place in 1970. Consisting of a green labelled mouse cell and a red labelled human cell. Cell types will mix over time.

Photobleaching Experiment

Membrane proteins were labelled with a fluorescent dye. Laser beam was used to bleach an area on the cell, and the fluorescent labels recovered.

One reason for cells to change fluidity

response to temperature

shorter tails and more double bonds (more unsaturation)

What conditions provide for increased membrane fluidity?

longer the tails and less double bonds (more saturation)

What conditions provide for decreased membrane fluidity?

Membrane bilayer is not permeable to…

Ions, large polar molecules,

Membrane bilayer is permeable to…

Non-polar molecules, and selectively for small non-polar.

Peptodoglycan

cell wall composed of carbohydrate and protein complex (prokaryotes)

Hydrophobic interior

A feature of cell interiors that happens to be a major barrier fro molecules crossing the cell membrane

Types of transmembrane transportation

diffusion, active transportation

Diffusion

Movement of molecules from an area of higher concentration to an area of lower concentration. Does not require use of cellular energy

Active Transport

Also known as anti-diffusion, moves from low concentration to high concentration. Requires use of cellular energy

simple diffusion

movement of a solute from an area of high concentration to an area of low concentration

facilitated diffusion

Movement of specific molecules across cell membranes through protein channels. Is controlled by cells via the presence or absence of a certain channel or carrier/activation-inactivation

channel proteins

provide corridors that allow a specific molecule or ion to cross the membrane

carrier proteins

a protein that transports substances across a cell membrane. Can do Ions, sugars, amino acids. requires binding and a concentration difference. Hit a maximum rate.

ion channel proteins

allow certain ions to diffuse across the plasma membrane passively. Open and close in response to stimuli. Direction of movement depends on concentration.

active transporters

Uniporters, symporters, antiporters

Uniporter

A carrier protein that transports a single molecule across the plasma membrane.

symporter

transporter that carries two different ions or small molecules, both in the same direction

antiporter

A carrier protein that transports two molecules acrss the plasma membrane in opposite directions.

Osmosis

Diffusion of water through a selectively permeable membrane

water potential

The physical property predicting the direction in which water will flow, governed by solute concentration and applied pressure.