Biology 1406 - Exam 1

cellular respiration

Taking energy from food and converting it into a form the cell can use

Catabolic

A process in which large molecules are broken down

ATP

(adenosine triphosphate) main energy source that cells use for most of their work, energy currency of the cell

Phosphorylation

The metabolic process of introducing a phosphate group into an organic molecule. ADP--ATP

Oxidation

The loss of electrons from a substance involved in a redox reaction.

reduction

The gain of electrons by a substance involved in a redox reaction; always accompanies oxidation.

aerobic respiration

Respiration that requires oxygen

Chemical overview of aerobic respiration

Glucose/Sugar(C6H12O6) + Oxygen(6O2) --> Carbon Dioxide(6CO2) + Water(6H2O) + Energy(ATP&Heat)

3 main steps of cell respiration

1. Glycolysis

2. Krebs Cycle

3. Electron Transport Chain

Coenzymes

nonprotein organic molecule that aids the action of the enzyme to which it is loosely bound

NAD+

(nicotinamide adenine dinucleotide) electron carrier involved in glycolysis; an important coenzyme in respiration

NADH

the reduced form of NAD+; an electron-carrying molecule that functions in cellular respiration

Glycolysis

-Most cells do it (Aerobic or Anaerobic)

-Happens in cytoplasm (NOT mitochondria)

-Does not require O2 or release CO2

-Requires 2 ATP

-10 steps of a series of enzyme mediated reactions

products of glycolysis

2 pyruvate, 2 ATP, 2 NADH

Krebs Cycle (Citric Acid Cycle)

-Happens in mitochondria (eukaryotes)

-Pyruvate from glycolysis is oxidized to acetyl-CoA

- Carbon is stripped and released as CO2

-NAD+ reduced to NADH

- 8 reactions mediated by enzymes

Products of Krebs Cycle

6 NADH, 2 FADH2, 4 CO2, 2 ATP

electron transport system

-Occurs in inner membrane of mitochondria

-Series of Redox. reactions

-Electrons push H+ across membrane to create Ion gradient

-Comes across membrane w/ the Ion gradient through certain proteins = ATP synthase

Products of Electron Transport Chain

34 ATP and water

Total ATP for whole process (per molecule of glucose)

-Glycolysis = 2

-Krebs Cycle = 2

-Electron Transport = 34

-Total =38~

Efficiency of Aerobic Cellular Respiration

40% (very efficient)

Anaerobic Pathways

-Do not us O2 as final electron receptor

-Bacteria, protist, yeasts, intestinal parasites

-Organisms in places devoid of O2

obligate anaerobes

organisms that cannot live where molecular oxygen is present

facultative anaerobes

can survive with or without oxygen (do both anaerobic and aerobic)

Fermentation

-Type of anaerobic respiration

-Bacteria and Yeasts

-Glycolysis is still first step

-Happens in cytoplasm

lactate fermentation

-Glycolysis followed by the reduction of pyruvate to lactate (lactic acid)

-Ex. Bacteria like Lactobacillus sp.

-Used commercially, lactic acid, flavors sour cream, yogurt, cheeses, etc.

alcoholic fermentation

-Pyruvate is converted to ethanol and CO2

-Ex. Yeasts like Saccharomyces

Element

Fundamental form of matter that cannot be broken down into something else

Atom

the smallest unit of an element that maintains the properties of that element

Protons

Positively charged subatomic particles found in the nucleus of an atom

Electron

a negatively charged subatomic particle found outside the nucleus in the electron cloud

Neutron

A subatomic particle that has no charge and that is found in the nucleus of an atom

atomic number

the number of protons in the nucleus of an atom

atomic mass

the sum of the protons and neutrons in an atom

Isotopes

Atoms of the same element that have different numbers of neutrons

ionic bond

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

covalent bond

A chemical bond that involves sharing a pair of electrons between atoms in a molecule

Molecule

two or more atoms held together, can be the same element (ex, O2, H2, N2)

Compound

A substance made up of atoms of two or more different elements joined by chemical bonds (ex. H20)

Ion

An atom or group of atoms that has a positive or negative charge. (a charged particle)

Cation

positively charged ion (lost electrons)

Anion

negatively charged ion (gained electrons)

double covalent bond

a bond in which two atoms share two pairs of electrons

Polarity

A lack of electrical symmetry in a molecule. Charge differences on opposite ends of a structure.

nonpolar covalent bond

A type of covalent bond in which electrons are shared equally between two atoms of similar electronegativity.

polar covalent bond

A covalent bond in which electrons are not shared equally and have unequal pull on electrons

hydrogen bond

Weak, temporary bond formed when an electronegative (polar) atom interacts with a H atom in another bond

Hydrophobic

Nonpolar, water fearing, ex. fats and oils

Hydrophilic

polar, water loving/soluble, ex. salts and simple sugars

Evaporation

permanently broken hydrogen bonds

Cohesion

Attraction between molecules of the same substance

Adhesion

An attraction between molecules of different substances

surface tension

A measure of how difficult it is to stretch or break the surface of a liquid

Solute

A substance that is dissolved in a solution (solevnt)

Solutions

A mixture of two or more substances.

Base

A substance that decreases the hydrogen ion concentration in a solution. (Accepts H+)

Acid

A substance that increases the hydrogen ion concentration of a solution. (Donates H+)

pH

the hydrogen ion concentration in a solution

organic compounds

one or more elements covalentely bonded with carbon

condensation/dehydration reaction

reaction that creates monomers; 2 molecules are covalently bonded through the loss of a water molecule

Hydrolysis/hydration reaction

Breaking down complex molecules by the chemical addition of water

Enzymes

Catalysts for chemical reactions in living things (proteins)

Carbohydrates

1:2:1 ratio of C:H:O (made up of 3 classes: monosaccharides, disaccharides, polysaccharides)

Monosaccharides

Single sugar molecules (glucose, fructose)

Oligosaccharides

short chains of 3 or more monosaccharides (at least 10); (lactose)

Polysaccharides

Carbohydrates that are made up of more than two monosaccharides (complex carbohydrates); (starch, cellulose, & glycogen)

Lipids

Energy-rich organic compounds, such as fats, oils, and waxes, that are made of carbon, hydrogen, and oxygen; very hydrophobic

Trigylcerides

lipids that have 3 fatty acids tails linked to glycerol used as a source of fuel

Phospholipids

a lipid consisting of a glycerol bound to two fatty acids and a phosphate group.

Sterols

A type of lipid based on cholesterol; includes testosterone and estrogen.

amino acids

building blocks of proteins

Nucleotide

A building block of DNA, consisting of a five-carbon sugar covalently bonded to a nitrogenous base and a phosphate group.

Biology

The study of life

Seven things all living things do

Reproduction, Energy Utilization, Respond to environment, Homeostasis, Order, Growth+Development, Evolutionary adaptation

Cell

The basic unit of structure and function in living things

cell theory

idea that all living things are composed of cells

cells are the basic units of structure and function in living things

and new cells are produced from existing cells

Levels of Biological Organization

biosphere, ecosystems, communities, populations, organisms, organs and organ systems, tissues, cells, organelles, molecules

emergent properties

result from the arrangement and interaction of parts within a system, "The whole is greater than the sum of the parts"

Robert Hooke

Discovered and named cells first using cork

Anton van Leeuwenhoek

First person to observe living cells and created many microscopes; first to describe protozoa and bacteria

prokaryotic cell

A type of cell lacking a membrane-enclosed nucleus and membrane-enclosed organelles; found only in the domains Bacteria and Archaea.

Eukaryotic cells

Larger, complex, with nucleus, membrane bound organelles, DNA in a nucleus

cell (plasma) membrane

phospholipid bilayer that protects and encloses the cell; controls transport; maintains homeostasis

fluid mosaic model

Structural model of the plasma membrane where molecules are free to move sideways within a lipid bilayer.

Nucleus

Control center of the cell, contains DNA, bound by double membrane (nuclear envelope)

Nucleolus

produces ribosomes (site of ribosome synthesis)

Ribosomes

site of protein synthesis in the cell

Rough Endoplasmic Reticulum

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

Smooth Endoplasmic Reticulum

An endomembrane system where lipids are synthesized

Golgi body

A structure in a cell that receives proteins and other newly formed materials from the ER, packages them, and distributes them to other parts of the cell.

Vesicles

small membrane sacs that specialize in moving products into, out of, and within a cell

Mitochondria

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

cell wall

A rigid layer of cellulose material that surrounds the cells of plants and some other organisms.

Chloroplast

organelle found in cells of plants and some other organisms that captures the energy from sunlight and converts it into chemical energy

central vacuole

in a mature plant cell, a large membranous sac with diverse roles in growth and storage

Cytoskeleton

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

Flagella

A long, whip-like filament that helps in cell motility. Many bacteria are flagellated, and sperm are flagellated.

Cilia

Hairlike projections that extend from the plasma membrane and are used for locomotion

Nucleoid

A non-membrane-bounded region in a prokaryotic cell where the DNA is concentrated.

Pili (pilus)

A protein filament that projects from the surface of some prokaryotic cells.

selectively permeable

a property of cell membranes that allows some substances to pass through, while others cannot