Final Exam Flashcards
Ionic Bond
Transfer of electrons (lost=positive charge, gained=negative charge)
OIL (Oxidation Is Losing)
RIG (Reduction Is Gaining)
Covalent Bond
Sharing electrons
Electronegativity
The pull for shared electrons
Nonpolar Covalent
Molecules of one element pull toward each atom equally
Polar Covalent
One molecule of different atoms attracts shared electrons more strongly than the other (in H2O oxygen attracts shared electrons more strongly than hydrogen)
H+
Hydrogen ion
OH-
Hydroxide ion
Acids
Higher H+ concentration
Bases
Higher OH- concentration, accepts hydrogen ions (H+) and removes them reducing H+ concentrations
Buffer
Chemical or combination of chemicals that keeps pH within normal limits
(seawater is buffered by carbon)
Hydroxyl Group
—OH
Carbonyl Group
> C=O
Carboxyl Group
—COOH
Amino Group
—NH2
Phosphate Group
—OPO3
Methyl Group
—CH3
Dehydration Reaction
BUILDS a polymer chain
Hydrolysis Reaction
BREAKS a polymer chain
Monosaccharide
Glucose & fructose
Polysaccharides
Monomers hooked together
Hydrophilic
Disaccharides
Two monosaccharides
Starch
Storage polysaccharide used by plants
Glycogen
Storage polysaccharide used by animals (liver/muscle cells)
Cellulose
Polysaccharide fibrils in plant cell walls
Chitin
Polysaccharide responsible for exoskeleton of insects and crustaceans, cell wall in fungus
Lipid
Glycerol & fatty acids (most molecules = glycerol + 3 fatty acids)
Hydrophobic (nonpolar C-H bonds)
Saturated Fatty Acid
No C-C double bonds
A hydrogen at every possible position
Solid at room temperature
Straight structure
Unsaturated Fatty Acid
One or more C-C double bonds
Fewer than max number of hydrogen
Liquid at room temperature
Bent structure (double bond)
Phospholipids
Two fatty acids attached to a glycerol & phosphate group
Phosphate group=hydrophilic
Fatty acid=hydrophobic
Steroids
Lipids with carbon skeleton of 4 fused carbon rings
Ex. Cholesterol (component in animal cell membranes to help keep them fluid, precursor from which all other steroids are synthesized, often hormones)
Protein
Polymer built from various combinations of 20 amino acid monomers
STRUCTURE = FUNCTION
Types: structural, contractile, defensive, signal, receptor, transport, storage
Enzyme
Proteins that serve as metabolic catalysts, regulate chemical reactions
Amino Acid
Building blocks of proteins; amino group & carboxyl group
20 amino acids
R groups determine shape, charge, weight
Primary Protein Structure
Chain of amino acids
Secondary Protein Structure
Coiling or folding of polypeptide
Coiling -> helical (alpha helix)
Folding -> pleated sheet
Tertiary Protein Structure
3D shape of protein
Quaternary Protein Structure
2 or more polypeptide chains (subunits) associated with
Rosalind Franklin
DNA structure
X-Ray Diffraction
Watson & Crick
Double helix
Base pairing
Cell Theory (1839, Theodore Schwann & Matthias)
- All life is composed of cells
- Cells are the basic unit of life
- Cells arise from already existing cells
Cell surface area
Small cells have more surface area relative to cell volume (more efficient)
Plasma membrane
Controls movement of molecules into and out of the cell
Selective permeability
Made of: lipids, proteins, some carbohydrates, abundant in phospholipids (phospholipid bilayer -> fluid mosaic model)
Nucleus
Contains genetic material, directs protein synthesis
Nuclear envelope (double membrane with pores)
Chromatin (DNA arranged on obvious chromosomes only when the cell is dividing, nucleoplasm)
Nucleolus (synthesis of ribosomal RNA occurs, assembled into ribosomal subunits)
Ribosomes
Involved in protein synthesis
Ribosomes are synthesized in the nucleolus
Cells requiring large amounts of proteins require large amounts of ribosomes
Locations: Attached on Rough ER & nuclear envelope, free in the cytoplasm
Contain rRNA
Smooth Endoplasmic Reticulum
Synthesis of lipids, oils, phospholipids, steroids
Catalyzes key step in mobilization of glucose from stored glycogen in liver
Storage of calcium
Rough Endoplasmic Reticulum
Production of phospholipids
Attached ribosomes produce proteins
Abundant in cells that secrete proteins
Package proteins in membrane
Golgi Apparatus
Manufacturing, warehousing, sorting, shipping
Modifying of proteins & lipids from ER into final form
Cis side: receives material -> fusing with vesicles from the ER
Trans side: buds off vesicles -> travel to other sites
Lysosome
Recycling and digesting cell material
Vacuoles
Contractile (enzymes for digestion, pigment vacuoles in plants for flower color, central vacuole in plants for defense compounds)
Food (from phagocytosis, fuse with lysosomes)
Contractile (found in freshwater protists, pump excess water out of the cell)
Mitochondria
Cellular respiration
Breakdown of glucose to form ATP
Powerhouse of the Cell
Chloroplast
Photosynthesis
Converts light energy to chemical energy of sugar molecules
Cytoskeleton
Microtubules -> cell shape, mitosis, flagellar movement, organelle movement
Actin filaments (microfilaments) -> support cell shape, cell movement
Intermediate filaments -> reinforce cell shape, fix organelle location
Tight Junctions
Prevent leakage
Anchoring Junctions
Fasten cells to sheets
Gap Junctions
Channels
Plasmodesmata
Communication between plant cells
Diffusion
Particles spread out evenly in an available space
Move from areas of high concentration to low concentration
Passive transport -> facilitated diffusion
Osmosis
Water moves across a membrane down the concentration gradient until equilibrium is reached
Osmoregulation
Isotonic
Concentration of solute is the same on both sides
Animal cell=normal
Plant cell=flaccid
Hypertonic solution
Solute concentration outside cell is higher than that of the cell
Animal cell=shriveled
Plant cell=plasmolyzed
Hypotonic solution
Solute concentration lower than that of the cell
Animal cell=lysed
Plant cell=turgid
Active transport
Moving a solute against its concentration gradient
Requires ATP
Exocytosis
Vesicles EXPORT bulky molecules
Endocytosis
Vesicles import substances useful to the livelihood of the cell
Phagocytosis=engulfment of a particle by vacuole
Pinocytosis=fluids taken in by small vesicles
Receptor-mediated endocytosis=receptor coated pits interact with a specific protein to form a vesicle
1st Law of Thermodynamics
Law of Energy Conservation
2nd Law of Thermodynamics
Energy conversions increase entropy (disorder) of the universe
Exergonic
Energy released
Endergonic
Energy consumed
Photosynthesis
Converts solar energy to chemical energy
Takes place in thylakoid membrane of chloroplast
6 CO2 + 6 H2O -> light energy -> C6H12O6 + 6 O2
Light reaction products=NADPH, ATP, O2
Calvin cycle occurs in stroma of chloroplasts -> products= 2 G3P to form 1 glucose
C4 Plants
Carbon fixation that saves water without stopping photosynthesis, bundle sheath cells
CAM Plants
Conserve water by opening their stomata and admitting CO2 only at night
Cellular Respiration
C6H12O6 + 6 O2 -> 6 CO2 + 6 H2O + ATPs
Produces ~32 ATP per glucose molecule
Glycolysis (glucose into 2 pyruvate, in cytoplasm)
Citric Acid Cycle (pyruvate into carbon dioxide, in mitochondria)
Oxidative Phosphorylation (electrons shuttled through ETC, in inner mitochondrion membrane)
Fermentation
Anaerobic energy-generating process
Produces -> 2 ATP, reduces NAD+ to NADH
Lactic Acid Fermentation
Alcoholic Fermentation
Asexual reproduction
Cloning, binary fission
Mitosis: budding, replacement cells, growth
Offspring identical
Less genetic diversity
Inheritance from one parent only
Sexual reproduction
Similar to parents, variations in traits
Inheritance of unique sets of genes from two parents
Interphase
G1 -> growth, increase cytoplasm, DNA repair
S -> DNA replication & growth
G2 -> growth, DNA repair, preparation for division
Mitotic (M) Phase
Mitosis=division of the nucleus
Cytokinesis=division of the cytoplasm
5 Stages:
Interphase -> chromosomes condense, mitotic spindles elongate
Prometaphase -> nuclear envelope disappears, spindle microtubules reach chromosomes, microtubules attach to centromeres of sister chromatids at kinetochore
Metaphase -> spindle fully formed, chromosomes align on metaphase plate, kinetochores face opposite poles of spindle
Anaphase -> chromatids separated, move towards opposite poles, microtubules attach to kinetochores & shorten, cell elongates
Telophase -> nuclear membrane forms, chromosomes unfold, microtubules disassemble
(Cytokinesis)
Oncogenes
Proto-oncogenes normally promote cell division
Mutations to oncogenes -> enhance activity
Tumor Suppressor Genes
Normally inhibit cell division
Mutations inactivate genes (uncontrolled division to occur)
Somatic Cells
Body cells
Pairs of homologous chromosomes
One of each pair from each parent
Homologous chromosomes
Same length
Same position of the centromere
Same loci
Sex chromosomes
X and Y
Only two chromosomes not matched in an identical pair
Autosomes
All chromosome pairs that are not X and Y
Meiosis
Reduces chromosome number (copy once, divide twice)
Meiosis 1
Separates homologous chromosomes
Chromosome number reduced by half
Haploid cells with replicated chromosomes
Meiosis 2
Separates sister chromatids
Chromosome number stays the same
Haploid cells with unreplicated chromosomes
Gregor Mendel - Advantages of Pea Plants
Controlled mating
Self fertilization
Observable, distinct characteristics
True breeding strains (self fertilization produces offspring identical to parent)
Law of Segregation
Genes are found in alternate versions (alleles)
Organism inherits two alleles
If alleles differ, one determines the organisms’ appearance
GENES IN A PAIR SEGREGATE DURING MEIOSIS AND EACH SPERM OR EGG RECEIVES INLY OND MEMBER OF THE PAIR
Test Cross
Determine genotype of individual with dominant phenotype by mating with homozygous recessive individual
Law of Independent Assortment
Each pair of alleles separates independently of all other pairs during gamete formation
Applies only to genes that are on different chromosomes or far apart on the same chromosome
Linked genes (near each other on the same chromosome) tend to be linked together
Nucleotide
Deoxyribose sugar
Phosphorus group
Nitrogen containing base
Which phase of the cell cycle is DNA replicated?
S phase
Origins of replication
Produce bubble
Proceeds in both directions from the origin
Ends when products from the bubbles merge with each other
DNA Helicase
Unzips the DNA helix -> breaks hydrogen bonds between bases
Single strand binding proteins
Keep unpaired template strands apart during replication
Polymerases
Place complementary nucleotides in fork
Adenine (A) with Thymine (T)
Cytosine (C) with Guanine (G)
Synthesis of DNA strands
Replication continuous on 3’ to 5’ template
Replication discontinuous on 5’ to 3’ template -> short segments
Lagging strand
Daughter strand synthesized in pieces
Okazaki fragments
Joined by DNA ligase
Leading strand
Daughter strand synthesized continuously
Requires formation of a single primer as the replication fork continues to separate
Transcription
DNA to RNA
Translation
RNA to protein
Stages of Transcription
Initiation -> RNA polymerase binds to promoter, helix unwinds & transcription starts
Elongation -> RNA nucleotides added to chain
Termination -> RNA polymerase reaches terminator sequence and detaches from template
