BIO 411 Final Exam

Single bond

a covalent bond in which two atoms share one pair of electrons

Double bond

A chemical bond formed when atoms share two pairs of electrons

covalent bond

A chemical bond formed when two atoms share electrons

Ionic bond

Formed when one or more electrons are transferred from one atom to another

Hydrogen bond

weak attraction between a hydrogen atom and another atom

polar molecules

Molecules that have an unequal distribution of charges

dehydration reaction

A chemical reaction in which molecules combine by removing water, cells make polymers from monomers

hydrolysis

Breaking down complex molecules by the chemical addition of water

enzymes

Catalysts for chemical reactions in living things

Carbohydrates

the starches and sugars present in foods

saturated fats

fats that are solid at room temperature

unsaturated fats

A fat that is liquid at room temperature and found in vegetable oils, nuts, and seeds.

Gene

A segment of DNA on a chromosome that codes for a specific trait

acid vs base

acid- high H+ (protons)- low scale number 0-7- donates protons (has to many)base- low H+- High scale number 7-14- accepts protons

Bonds from strongest to weakest

covalent, ionic, hydrogen

Cytoskeleton

A network of fibers that holds the cell together, helps the cell to keep its shape, and aids in movement

extracellular matrix

The substance in which animal tissue cells are embedded, consisting of protein and polysaccharides.

cell-cell junctions

they form a cohesive layer via intercellular junctions
they provide direct pathways for communication between neighboring cells or between cells and the extracellular matrix

generally composed of cell adhesion molecules (CAM)

Electronegativity

A measure of the ability of an atom in a chemical compound to attract electrons

Endosymbiont Theory

explains that eukaryotic cells may have evolved from prokaryotic cells

Isomer

Compounds with the same formula but different structures.

Eukaryotic cells

Contain a nucleus and other organelles that are bound by membranes.

Prokaryote cell

single-celled organism without a nucleus

Diffusion

Movement of molecules from an area of higher concentration to an area of lower concentration.

concentration gradient

A difference in the concentration of a substance across a distance.

passive transport

the movement of substances across a cell membrane without the use of energy by the cell

active transport

Energy-requiring process that moves material across a cell membrane against a concentration difference

Catabolic pathways

Metabolic pathways that release energy by breaking down complex molecules into simpler compounds.

Anabolic pathways

Metabolic pathways that consume energy to build complicated molecules from simpler ones

exergonic reaction

A spontaneous chemical reaction in which there is a net release of free energy.

exogonic reaction

A chemical reaction that releases energy

Competitive inhibitors

bind to the active site of an enzyme, competing with the substrate

Noncompetitive inhibitors

bind to another part of an enzyme, causing the enzyme to change shape and making the active site less effective

Cellular respiration

Process that releases energy by breaking down glucose and other food molecules in the presence of oxygen

Gibbs Free Energy

the energy of a system that is available to do work at a constant temperature and pressure

How do enzymes speed up reactions?

by lowering the activation energy

Redox reaction

A chemical reaction involving the transfer of one or more electrons from one reactant to another; also called oxidation-reduction reaction.

Oxidation

loss of electrons

reduciton

gain of electrons

pathways of cellular respiration

glycolysis, citric acid cycle, electron transport chain

glycolysis

the breakdown of glucose by enzymes, releasing energy and pyruvic acid.

Glycolysis inputs and outputs

Inputs: glucose, 2 ATP
Outputs: 2 pyruvic acids, 2 net ATP (4 ATP), NADH

substrate-level phosphorylation

The enzyme-catalyzed formation of ATP by direct transfer of a phosphate group to ADP from an intermediate substrate in catabolism.

Citric acid cycle inputs and outputs

Inputs: Acetyl-CoA, two acetyl groups (same)
Outputs: CO2, two ATP, six NADH, two FADH2

oxidative phosphorylation

The production of ATP using energy derived from the redox reactions of an electron transport chain; the third major stage of cellular respiration.

oxidative phosphorylation inputs and outputs

Inputs: 10 NADH, 2 FADH2
outputs: 26-28 ATP

chemiosmosis

A process for synthesizing ATP using the energy of an electrochemical gradient and the ATP synthase enzyme.

fermentation

Process by which cells release energy in the absence of oxygen

alcohol fermentation

Glycolysis followed by the reduction of pyruvate to ethyl alcohol, regenerating NAD+ and releasing carbon dioxide.

lactic acid fermentation

the chemical breakdown of carbohydrates that produces lactic acid as the main end product

two stages of Photosynthesis

light reactions and calvin cycle

Light reactions

The first of two major stages in photosynthesis (preceding the Calvin cycle). These reactions, which occur on the thylakoid membranes of the chloroplast or on membranes of certain prokaryotes, convert solar energy to the chemical energy of ATP and NADPH, releasing oxygen in the process.

Calvin cycle

reactions of photosynthesis in which energy from ATP and NADPH is used to build high-energy compounds such as sugars

Metabolism

All of the chemical reactions that occur within an organism

Metabolic pathway

A series of chemical reactions that either builds a complex molecule or breaks down a complex molecule into simpler compounds

Spontaneous process

A process that occurs without an overall input of energy; a process that is energetically favorable.

Nonspontaneous process

a reaction that needs additional energy to proceed; includes endergonic reactions

Activation energy

Energy needed to get a reaction started

origins of replication

Site where the replication of a DNA molecule begins, consisting of a specific sequence of nucleotides.

replication fork

A Y-shaped region on a replicating DNA molecule where new strands are growing.

histones

protein molecules around which DNA is tightly coiled in chromatin

nucleosome

repeating subunit of chromatin fibers, consisting of DNA coiled around histones

restriction enzymes

Enzyme that cuts DNA at a specific sequence of nucleotides

Transcription

synthesis of an RNA molecule from a DNA template

Translation

Process by which mRNA is decoded and a protein is produced

Codon

A specific sequence of three adjacent bases on a strand of DNA or RNA that provides genetic code information for a particular amino acid

nucleotide-pair substitution

the replacement of one nucleotide and its partner with another pair of nucleotides

Silent mutations

have no effect on the amino acid produced by a codon because of redundancy in the genetic code

Missense mutations

change one amino acid to another

Nonsense mutations

A mutation that changes an amino acid codon to one of the three stop codons, resulting in a shorter and usually nonfunctional protein.

operon

group of genes operating together

operator

Region of DNA that controls RNA polymerase's access to a set of genes with related functions.

repressor

A protein that suppresses the transcription of a gene.

regulatory gene

A gene that codes for a protein, such as a repressor, that controls the transcription of another gene or group of genes.

differential gene expression

The expression of different sets of genes by cells with the same genome.

control elements

segments of noncoding DNA in eukaryotic genes that help regulate transcription by binding to certain proteins.

Reception

The target cell's detection of a signal molecule coming from outside the cell.

Transduction

conversion of the signal to a cellular response

Response

a reaction to a stimulus

M Phase

mitosis and cytokinesis

Mitosis

division of the nucleus

Cytokinesis

division of the cytoplasm

G1 phase

Cell growth

S phase

DNA replication

G2 phase

The second growth phase of the cell cycle, consisting of the portion of interphase after DNA synthesis occurs.

binary fission

A form of asexual reproduction in single-celled organisms by which one cell divides into two cells of the same size

Prophase

Chromosomes become visable, nuclear envelop dissolves, spindle forms

Prometaphase

The second stage of mitosis, in which the nuclear envelope fragments and the spindle microtubules attach to the kinetochores of the chromosomes.

Metaphase

Chromosomes line up in the middle of the cell

Anaphase

Phase of mitosis in which the chromosomes separate and move to opposite ends of the cell

Telophase

After the chromosome seperates, the cell seals off, Final Phase of Mitosis.

meisosis

makes sex cells

cell cycle control system

A cyclically operating set of molecules in the eukaryotic cell that both triggers and coordinates key events in the cell cycle.

homozygous gene

a gene composed of two identical alleles

Heterozygous

An organism that has two different alleles for a trait

phenotype

An organism's physical appearance, or visible traits.

Genotype

genetic makeup of an organism

law of independent assortment

the law that states that genes separate independently of one another in meiosis

nondisjunction

Error in meiosis in which homologous chromosomes fail to separate.

apoptosis

programmed cell death