BIO Exam 2

Chapter 4, 6, 7

active transport

molecular movement that depends on the input of energy, which is necessary when the molecules to be moved are large or being moved against their concentration gradient

carrier protein

type of cell membrane protein involved in facilitated diffusion and active transport of substance out of or into the cell

cell

the smallest unit of life that can function independently

cell theory

a unifying and universally accepted theory in biology that holds that all living organisms are made up of one or more cells and that cells arise from other, preexisting cells

cell wall

a rigid structure, outside the cell membrane that protects and gives shape to the cell

centrioles

structures located outside the nucleus in most animal cells, to which the spindle fibers are attached during cell division

cillia

short projections from the cell surface, often occurring in large numbers on a single cell that beat against the extracellular fluid to move fluid past the cell

chloroplast

the organelle in plant cells in which photosynthesis occurs

cholesterol

an important part of most cell membranes, helping the membrane maintain its flexibility

concentration gradient

the gradual change in the concentration of solutes in a solution

cytoplasm

the contents of a cell contained within the plasma membrane

cytoskeleton

a network of proteins structures in the cytoplasm of eukaryotes that serves as scaffolding, sometimes giving a cell its characteristic shape

diffusion

passive transport in which a particle is dissolved in a gas or liquid and moves from an area of higher solute concentration to an area of lower solute concentration (with/down the concentration gradient)

endocytosis

a cellular process in which large particles outside the cell are engulfed by the cell membrane

endomembrane system

a system of organelles that surrounds the nucleus (rough ER, smooth ER, and Golgi)

endosymbiosis theory

theory of the origin of eukaryotes involving the development of prokaryotes into the chloroplasts and mitochondria

enzymatic proteins

proteins that initiate and accelerates a chemical reaction in a living organism

eukaryote

an organism composed of eukaryotic cells ex: plants, animals, fungi, and protists

eukaryotic cell

a cell with a membrane-surrounded nucleus that contains DNA, membrane surrounded organelles, and internal structures organized into compartments

exocytosis

a cellular process in which particles within in the cell are transported out of the cell

facilliated diffusion

diffusion of molecules through the phospholipid bilayer of plasma membrane that takes place through a transport protein embedded in the membrane

flagellum

a long, thin, whip-like projection from a cell that aids in cell movement

fluid mosaic model

a term that describes the structure of the plasma membrane, which is made up of different types of molecules, many of which not fixed in place, held in their proper orientation by hydrophilic and hydrophobic forces

Golgi apparatus

an organelle, part of the endomembrane system, structurally like a flattened stack of unconnected membranes that label and pack molecules for transport

Hydrophilic

attracted to water

Hydrophobic

repelled by water

invagination theory

the theory that the endomembrane system of eukaryotes was formed by the folding of a membrane so that an outer surface becomes an inner surface

lysosome

a round, membrane-enclosed enzyme and acid-filled vesicle in the cell that digests and recycles cellular waste products and consumed material

Mitochondria

the organelle in eukaryotic cells that converts energy stored in food into a form usable by the cell for its functions and activities (ATP)

non-polar

not electrically charged

nuclear membrane

a membrane enclosing the nucleus of a cell, separating it from the cytoplasm

nucleus

a membrane-enclosed structure in eukaryotic cells that contains the organism’s genetic information as linear strands of DNA in the form of chromosomes

organelle

specialized structure in the cytoplasm of eukaryotic cells, with specific functions

osmosis

a type of passive transport in which water molecules move across a membrane

passive transport

molecular movement that occurs spontaneously, without the input of energy

phagocytosis

one of the three types of endocytosis in which relatively large solid particles are engulfed by the plasma membrane for transportation into the cell; cellular eating

phospholipid

a group of lipids that are the major components of the plasma membrane

phospholipid bilayer

the structure of the plasma membrane in which two layers of phospholipids are arranged tail to tail

pilus

a thin, hair-like projection that helps a prokaryote attach to surfaces

pinocytosis

one of three types of endocytosis in which dissolved particles and liquids are engulfed by the plasma membrane for transportation into the cell; cellular drinking

plasma membrane

a complex, thin, two-layered membrane that encloses the cytoplasm of the cell, holding contents in place and regulating what leaves and enters

polar

having an electric charge

prokaryote

an organism consisting of a prokaryotic cell ex: bacteria

prokaryotic cell

a cell bound by the plasma membrane enclosing the cell’s contents (cytoplasm, DNA, and ribosomes); this kind of cell has no nucleus or other organelles

pumping

form of active transport involved with moving up/against the concentration gradient

receptor mediated endocytosis

one of the three types of endocytosis, in which receptors on the surface of a cell bind to specific molecules allowing the molecule to enter the cell

recognition protein

a protein in the plasma membrane that provides a fingerprint on the outside surface of the cell making it recognizable to other cells

ribosome

granular bodies in the cytoplasm, consisting of proteins and RNA, that are involved in using information in the mRNA to synthesize proteins

rough endoplasmic reticulum

an organelle, part of the endomembrane system, structurally like a series of interconnected flattened sacs connected to the nuclear envelope. Its surface is studded with ribosomes. It is involved in making complex proteins.

self-marker

a kind of fingerprint that identifies the cell

simple diffusion

diffusion of molecules directly through the phospholipid bilayer of a plasma membrane without the assistance of other molecules

smooth endoplasmic reticulum

an organelle, part of the endomembrane system, structurally like a series of branched tubes. Its surface has no ribosomes. It makes lipids and detoxifies substances

solute

a substance that is dissolved in liquid or gas

solution

both the solute and the solvent

solvent

the gas or liquid in which a substance is dissolved

surface protein

a protein that resides primarily on the inner or outer surface of the phospholipid bilayer that constitutes a cell’s plasma membrane

transmembrane protein

a membrane protein that penetrates the phospholipid bilayer of a cell’s plasma membrane

vaculoe

a membrane-enclosed, fluid-filled multipurpose organelle prominent in most plant cells. It serves as storage in the cell

vesicle

a small, membrane, enclosed sac within a cell

Prokaryotic and Eukaryotic

What are the two types of cells?

DNA is stored in the cytoplasm and in the form of a singular circular chromosome

Where and in what form in DNA found in prokaryotic cells?

DNA is stored in the nucleus and in the form of multiple linear chromosomes

Where and in what form is DNA found in eukaryotic cells

Cell wall, capsule, pili, and flagellum

What are the four additional structures that may be present in prokaryotes?

Centriole

Which organelle is specific to animal cells?

vacuole, chloroplasts, and cell wall

Which organelles are specific to plant cells?

are similar in size, divide by splitting, have their own ribosomes, have small amounts of circular DNA, have a double membrane, and are involved in energy conversions

Evidence supporting the endosymbiosis theory states that both chloroplasts and mitochondria … similar to bacteria

The nucleus, rough ER, smooth ER, and Golgi all have inner and outer membranes suggesting that the cell got too large and folded in on itself creating these structures

What evidence is there to support invagination theory?

Phospholipid bilayer, carbohydrate chains, cholesterol, receptor proteins, and transport proteins (channels, carriers, and pumps)

Five components of the plasma membrane

Which areas of the plasma membrane are hydrophobic and hydrophilic?

The internal section is hydrophilic and the external section is hydrophobic

amino acid

one of the twenty molecules built of an amino group, a carboxyl group, and a unique side chain

polypetide

a chain of amino acids linked together to form all or part of a protein molecule

anticodon

a sequence of three nucleotides forming a unit of genetic code in a tRNA molecule

nucleotide base

one of the nitrogen-contain side chain molecules attached to a sugar molecule in the sugar-phosphate backbone of DNA and RNA

base pair

two nucleotides on complementary strands of DNA that form a pair, linked by hydrogen bonds

capping

adding a modified nucleotide to the from of mRNA which protects it from degradation by enzymes in the cytoplasm

central dogma

DNA-→ RNA-→ Proteins through the processes of transcription and translation

chromosome

a linear or circular strand of DNA with specific sequences of base pairs

chromosomal aberrations

a type of mutation characterized by a change in the overall organization of genes on a chromosome

coding region

section of DNA that codes for a protein

codon

three-base sequence in mRNA that linked with complementary tRNA molecules

deoxyribonucleic acid (DNA)

a nucleic acid that carries information in the sequence of its nucleotide bases, about the production of particular proteins

proteins

one of the four type of biological macromolecules, constructed of a unique combination of 20 amino acids that result in unique structures and chemical behavior

gene

a sequence of DNA nucleotides on a chromosome that carry the information necessary for making a functional product, usually a protein, or an RNA molecule

genome

the full set of DNA present in an individual organism

intron

a noncoding region of DNA

locus

the location or position of a gene on a chromosome

messenger RNA (mRNA)

the ribonucleic acid that reads the sequence for genes in DNA and then carries the information from the nucleus to the cytoplasm, where the next stage of protein synthesis takes place

mRNA editing

post-transcription process in which introns are removed and exons are spliced together

mutation

an alteration in the base-pair sequence of an indivisual’s DNA

may arise spontaneously or following exposure to a mutagen

Mutation sources

non-template strand

strand of DNA that is not used during transcription

non-coding region

rection of DNA that does not code for proteins

nucleic acid

one of the four types of biological macromolecules, involved in information storage and transfer

nucleotide

a molecule containing a phosphate group, a sugar molecule, and a nitrogen-containing base

point mutations

a type of mutation in which one base pair in DNA is changed

promoter sequence

part of a DNA molecule that indicates where the sequence of base pairs that make up a gene begin

protein synthesis

the construction of a protein from its constitute amino caids, by the process of transcription and translation

psuedogene

DNA sequence that resembles a gene but produces no protein

RNA polymerase

enzyme used to facilitate transcription

reading frame

way of reading nucleotide sequences used by tRNA