Bio Test 2 Flashcards
Prokaryote
Unicellular organisms have this type of cell. Some features include:
- Not having a nucleus
- Lacks organelles, organization
- Smaller than eukaryotes
Eukaryote
Multicellular organisms have this type of cell. Some features include:
- Having a nucleus
- Having organelles
- Larger than prokaryotes
Cilium (Cilia)
- Present in eukaryotes only
- Functions to either move the cell itself or move things outside the cell (in the environment)
- Tiny hair-like threads on the surface of the cell (but still considered membrane-bound)
Flagellum (Flagella)
- Present in both prokaryotes and eukaryotes (sperm cell is the only flagellum in the human body)
- Motile
- Thread-like tail structure
Osmotic Bursting / Cytolysis / Osmotic Lysis
When the cell bursts due to an osmotic imbalance. The cell gains too much water through diffusion and ends up rupturing. Cell wall prevents this phenomenon.
Cell Wall
- Found in some prokaryotes and some eukaryotes (plants)
- Mainly made of cellulose
- Covers the cell membrane
- Provides protection; tough surface
- Prevents osmotic bursting
- Fully permeable
Pilus (Pili)
- Found only in prokaryotes
- Functions to help cells with adhesion or attachment to other cells
- Thin and hair-like structure, smaller than a flagellum
Nucleoid
Region in a prokaryote where DNA is found
Glycocalix / Capsule / Slime Layer
- Sticky outer layer of a prokaryote
- Glycocalix means “sugar coat”
- Made of polysaccharides and proteins
- Helps bacteria evade immune system more easily
Biofilm
Groups of bacteria sticking together, creating slimy coatings to protect them
3 Domains of Life are…
- Archaea (prokaryotic)
- Bacteria (prokaryotic)
- Eukarya (eukaryotic)
Gram-positive
Thick cell wall:
- Thick peptidoglycan layer
- No outer membrane
- Retains color in gram staining
Gram-negative
Thin cell wall:
- Thin peptidoglycan layer
- Has an outer membrane (lipopolysaccharides)
- Does not retain color in gram staining
Gram Staining
Involves crystal violet dye, iodine solution, and ethyl alcohol or acetone.
- Crystal violet dye + iodine solution form crystal violet-iodine complex
- Ethyl alcohol or acetone dehydrates peptidoglycan layer, causing it to shrink
- In gram-positive bacteria, the violet-idoine complex cannot penetrate the shrunken peptidoglycan layer, causing it to have a purple color
- In gram-negative bacteria, the peptidoglycan layer is too thin to hold the complex crystals, causing color to be lost
Differential Staining
A technique where you use different dyes to stain different microorganisms on a slide, allowing you to differentiate between the two of them more easily
Lipopolysaccharide (LPs)
- Part of the outer membrane in gram-negative bacteria (and the outer membrane is part of the cell wall)
- Consists of a lipid and polysaccharide
- Endotoxin, harms the human body
Peptidoglycan
- Part of the cell wall in bacteria
- Thicker layers in gram-positive bacteria
- Thinner layers in gram-negative bacteria
- Made of, as the name implies, glycan (anything with glycosidic linkages) chains and short peptides
Nucleus
- Where DNA is stored
- Contains the nucleolus
- Contains chromatin
- Has a nuclear membrane made of two layers
- Has nucleus pores
Nuclear DNA
- Term used to describe DNA found in the nucleus of a cell
- Both paternal and maternal DNA
Histones
Proteins in chromatin that help give structure to chromosomes (made of DNA)
Chromatin
Histones + DNA
Nucleolus
- Transcribes/Produces rRNA
- Produces ribosomes
Nuclear Membrane / Nuclear Envelope
- Made of two phospholipid bilayers (inner and outer)
- Semi-permeable
Nucleus Pores
- Holes in the nuclear membrane
- Allows select molecules to pass (such as RNA)
Rough Endoplasmic Reticulum
- Site of protein synthesis (produces proteins)
- Contains ribosomes
- Makes membrane
Ribosomes
- Functions to actually synthesize and produce proteins
- Found in the rough ER
- Made in the nucleolus
- Has a large subunit and small subunit
- Made of rRNA and protein
Smooth Endoplasmic Reticulum
- Synthesizes lipids
- Metabolizes carbohydrates
- Detoxification of drugs and poisons
- Makes vesicles (membranes of phospholipid bilayer + proteins)
Golgi Apparatus
- Modifies lipids and proteins
- Sends them to destinations in vesicles
- Produces vesicles just like the smooth ER does
DNA Cycle
DNA → mRNA → out of nuclear pores → rough ER → ribosome → protein → smooth ER → vesicle → golgi apparatus → vesicle → cell membrane
Mitochondrion (Mitochondria)
- Found in eukaryotic cells
- Produces ATP via cellular respiration
- Has its own ribosomes (can make proteins)
- Has its own DNA
- Mitochondrial DNA is maternal only
Lysosome
- ONLY for animal cells, NOT in plant cells
- Has hydrolytic enzymes (enzymes involved in hydrolysis)
- Involved in breaking down worn-out or excess cell parts
- Can also destroy viruses or bacteria
- “Clean up” organelle
Central Vacuole
- ONLY for plant cells and fungi cells, NOT in animal cells
- Stores chemicals for later use
- Stores water to provide rigidity
- Stores macromolecules
- Storage organelle in plants
Chloroplast
- Only in plants
- Converts CO2 and H2O into sugar using light energy
- Has its own ribosomes
- Has its own DNA
- Made of thylakoids (in grana) and stroma
- Contains chlorophyll in grana
Thylakoid
- Flattened sacs in chloroplasts
- Photosynthesis takes place here
- Stacks of thylakoids are called grana (singular: granum)
Granum (Grana)
Stacks of thylakoids
Stroma
- Colorless fluid around the grana in chloroplasts
- Photosynthesis is started here and finished in thylakoids
Centrosome
- Only found in animal cells
- Gives structure to cell
- Primary microtubule-organizing center (MTOC), moves microtubules around, aka shifts cytoskeleton
- “Funny” vacuole
- Contains centrioles
Centriole/Centrosome
- Produces spindle fibers used to move chromosomes around the cell during mitosis (centriole)
- Involved in flagella and cilia formation (centrosome)
- Helps determine locations of organelles in the cell (centrosome)
Cytoskeleton
- Gives cell its structure
- Consists of 3 components: microtubules, microfilaments, and intermediary filaments
Endomembrane System
- How membrane-bound organelles interact
Fluid Mosaic
The idea that the plasma membrane is made of a mix of lipids, proteins, and carbohydrates
Plasma Membrane
- Aka cell membrane
- Phospholipid bilayer
- Selectively permeable, allows only specific molecules to pass
Membrane Fluidity
- Viscous: saturated hydrocarbon tails, straight
- Fluid: unsaturated hydrocarbon tails, kinked
- Cholesterol can fill in, making saturated tails more fluid and unsaturated tails more viscous (good balance)
Glycoprotein
- Protein attached to oligosaccharide
- Modified protein
- Involved in cell-to-cell recognition, virus-to-cell recognition, bacteria-to-cell recognition
- On the outside of a plasma membrane with the oligosaccharde facing out
Glycolipid
- Lipid attached to oligosaccharide
- Modified lipid
- Involved in cell-to-cell recognition, virus-to-cell recognition, bacteria-to-cell recognition
- On the outside of a plasma membrane with the oligosaccharde facing out
Phospholipid Movement
- Flips laterally (horizontally) about 10 million times per second
- Flip-flops or switches vertically about once per month
Simple Diffusion
- Passive transport
- Involves either hydrophobic molecules or small, uncharged, and polar molecules
Facilitated Diffusion
- Passive transport
- Involves either ions or large and polar molecules (even if uncharged)
Transmembrane Protein
- Spans the whole membrane
- Nonpolar amino acids interact with the phospholipid bilayer
- Polar amino acids face outside and make a kind of channel to facilitate diffusion of polar molecules
- Often coiled in alpha helixes, helical bundles, or beta barrels
Membrane Proteins help with…
- Intercellular joining
- Enzymatic activity
- Transport (active or passive)
- Cell-to-cell recognition (glycoproteins)
- Signal transduction
Active Transport
- Uses energy from ATP to transport molecules
- Against the gradient
- Carrier changes shape
- Produces a concentration gradient
Passive Transport
- Does not use ATP energy
- Small molecules can passively diffuse through membranes
- With the gradient
- Larger molecules and ions enter through proteins (channel proteins or passive carrier proteins)
- Diffusion is ALWAYS passive
Aquaporin
Channel protein that allows water to pass
Gradient
- Low concentration on one side and high concentration on the other
- A form of potential energy (PE)
Glute
Carrier protein that allows glucose to pass (passive transport)
ATP Hydrolysis
Breaks down ATP into ADP and inorganic phosphate (Pi), also ATPase activity
Phosphorylation
Pi binds to a molecule and changes its shape; verb is ‘phosphorilate’
Conformational Change
Shape change of a protein due to phosphorilation; changes the protein’s function due to the change in shape
Dephosphorylation
Loses the inorganic phosphate that bonded to the molecule
Na+/K+ pump (Sodium-Potassium ATPase or pump)
Involves ATP hydrolysis, phosphorilation, conformational change, dephosphorilation to actively transpor Na+ and K+ ions
Proton Pump + Sucrose-H+ Cotransporter
- Proton pump uses ATP to transport protons (H+) against the gradient
- Protons eventually diffuse back into the cell but also cotransport sucrose, which can be used to create ATP
Bulk Transport
- For large molecules to pass
- Requires ATP
- Includes exocytosis and endocytosis
- Also for cells “eating” (engulfing) other cells
Exocytosis
Transport large molecules out of the cell
Endocytosis
Transport large molecules into the cell
Pinocytosis
Cell eats droplets of extracellular fluid with molecules in it, nonspecific process, endocytosis
Phagocytosis
Cell eats bacteria or another cell
Macrophage
“Big eater” cell eating
Antibodies
Cause viruses to become sluggish and easier to destroy
Pseudopod / Pseudopodium
Temporary extensions of the cytoplasm to wrap around the bacteria, cell, or molecule and engulf it
Amoeba
A single eukaryotic cell
Protozoa
A type of parasite
Receptor-mediated Endocytosis
Binds to a receptor and then pseudopod engulfs it
Low-density Lipoprotein (LDL) Cholesterol
- “Bad” cholesterol, can lead to build-ups
- Cholesterol surrounded by proteins and phospholipid coat
Metabolism
Totality of an organism’s chemical reactions
Catabolic Reaction
Reaction that involves breaking things down (like hydrolysis)
Anabolic Reaction
Reaction that involves building/synthesizing things (like dehydration)
Metabolic pathways
- Can be linear or cyclic or branched
- Pathways for chemical reactions
Nucleoside
A nucleotide without any phosphate
Distal or Terminal Phosphate Group
The last, most distant phosphate group from the rest of the structure
First Law of Thermodynamics
Energy cannot be created or destroyed (same with matter)
Second Law of Thermodynamics
During energy transfer, energy is lost to the environment as heat
Exergonic
- Spontaneous
- Passive
- Decrease in energy
Endergonic
- Nonspontaneous
- Active
- Requires energy
Energy Gradient
Difference in energy on different sides of a membrane
Coupling
When energy is released during a spontaneous process and the energy released is used to allow a nonspontaneous reaction to occur
ATP Gibbs Free Energy
-7 kcal/mol
What is the final acceptor on the ETC?
Oxygen due to electronegativity
Ribosimes
Ribosomal Enzymes
Hexokinase
Kinase adds phosphate group, hexokinase adds phosphates to 6-carbon sugars
Anabolic Enzyme
Enzyme involved in synthesis
Two models for enzymes
- Lock-and-key model (self, explanatory)
- Induced-fit model (fits around the enzyme, not like a lock and key)
Cofactor
- Non-protein
- Inorganic compound
- Neutral ion
- Divalent (could make a +2 charge like Mg, Ca, Mn)
- Enzyme helper
Coenzyme
- Small organic molecules
- Enzyme helper
Apoenzyme
Inactive enzyme
Holoenzyme
Active enzyme (w/ helper)
What is the optimal temperature for human enzymes?
98.6°F or 37°C
Thermus Aquaticus
Hot water (70 degrees Celsius)
Bacteria found in hot springs and is eally usful dfodf somdkj
Acidophile
Likes acidic environments
Neutrophile
Likes neutral (pH-wise) environments
Inhibitor
- Interferes w/ ES complex
- Competitive (competes directly) vs Noncompetitive (changes the shape of the enzyme)
- Reversible vs Irreversible
Allosteric Control
- Allosteric Activator (locks protein in active state, bonds elswhere to activate)
- Allosteric Inhibitor (locks protein in inactive form, bonds elsewhere to inhibit)
Cooperativity
- Is a type of allosteric control
- Substrate causes subunit to activate, which then causes the next subunit to activate and so on
Feedback Inhibition
Enzyme’s end product binds to enzyme as an allosteric inhibitor to prevent more product from forming (prevent enzyme from activating and working)
Cellular Respiration Equation
C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + ATP + Heat
Electron Carrier
- Carries Electrons to the Electron Transport Chain (Oxidative Phosphorilation)
- NADH, FADH₂ (reducing agents too)
3 Stages of Cellular Respiration
- Glycolysis
- Citric Acid Cycle / KREBS Cycle / Tricarboxylic Acid Cycle (TCA Cycle)
- Oxidative Phosphorilation / Electron Transport Chain (ETC)
Substrate-level Phosphorylation
Transfer of phosphate from a substrate to ADP molecule to generate ATP
Step 1 of Glycolysis
- Begins w/ glucose
- Enzyme hexokinase involved
- Add phosphate group
- Produces glucose 6-phosphate
- Committed/Irreversible step (uses ATP)
Step 2 of Glycolysis
- Starts w/ glucose 6-phosphate
- Enzyme phosphoglucose isomerase involved
- Produces fructose 6-phosphate
- Noncommitted/Reversible step
Step 3 of Glycolysis
- Begins w/ fructose 6-phosphate
- Uses pfk or phosphofructokinase
- Adds phosphate group
- Produces fructose 1, 6-biphosphate
- Committed/Irreversible step (uses ATP)
Glycolysis (what to know overall)
- Starts w/ glucose
- Ends w/ pyruvate
- Pyruvate gets converted into something else (CoA) to go to the TCA cycle
- Net x2 ATP
- Makes NADH as well
- Aerobic
KREBS Cycle
- CO₂ comes off
- NADH produced
- x2 ATP
- FADH₂ produced
- Many intermediates
- Aerobic
ETC
- Electron transport chain
- Redox!!
- H⁺ protons cross the membrane when redox reactions occur
- Aerobic
- ATP synthase allows H⁺ protons to pass the innermitochondrial membrane into the mitochondrial matrix
- Chemiosmosis occurs - diffusion of H⁺ ions across ATP synthase, also produces ATP
- ATP synthase and chemiosmosis are coupled processes
ATP Synthase
Allows H⁺ protons to cross the membrane into the mitochondrial matrix
Chemiosmosis
Diffusion of H⁺ protons across the membrane down the gradient, resulting in ATP
Enzymes in ETC
- NADH reductase
- Succinate Dehydrogenase
- Cytochrome reductase
Fermentation
- Alcohol fermentation (produces alcohol)
- Lactic acid fermentation (produces lactic acid)
- Anaerobic
- Only produces x2 ATP
Amylase
Breaks down starch
