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Biology chapter 7-11
Introduction to zoology midterm exam
87
Biology
Undergraduate 1
02/11/2011

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Term
Organelles
Definition
membrane bound compartments providing different internal environment than rest of cell
Term
Cytosol
Definition
fluid portion of cytoplasm
Term
Nucleus
Definition
site of DNA storage and use
Term
Ribosomes
Definition

site of protein syntesis

-can be free or bound to membranes.

Term

Endoplasmic Reticulum (ER)

 

Definition
network of membrane continuous with outer nuclear membrane
Term
Smooth (ER)
Definition

no ribosomes

-site of lipid metabolism

Term
Rough (ER)
Definition

studded with ribosomes 

-site of protein synthesis

Term

Golgi Apparatus 

 

Definition

flattened, membrane sacs 

-pics up products from ER

-ships to destination

-site of protein modification

Term

Lysosomes

 

Definition
contain enzymes for breakdown of food, waste and other stuff
Term

endocytosis

 

Definition
vesicles form from outside membrane and bring stuff into cell-merge with lysosome.
Term
phagocytosis
Definition
bring in food
Term
pinocytosis
Definition
bring in fluid
Term
receptor mediated
Definition
substances are specific to receptor.
Term
autophagy
Definition
damaged organelles carried to lysosomes
Term
Mitochondria
Definition

production of ATP from organic molecules or cellular respiration.

-double membrane

-inner membrane froms cristae

-intermembrane and matrix

-DNA and ribosomes-production of own proteins 

-grow and divide independently of the rest of cell

Term
Chloroplasts
Definition
formation of organic molecules using sun's energy
-double membrane
-thylakoids-stacks (grana) of membrane disks
-circular DNA along with ribosomes
Term
Cytoskeleton
Definition
network of protein filaments
-support and movement
Term
Cell Wall
Definition
fungi, algae, plants
-support
Term
actin filaments (microfilaments)
Definition
actin is a protein
-maintain cell shape
-cell movement along with protein
-cell division
Term
intermediate filaments
Definition
protein keratin plus others
-network of support beams for cell shape
-anchors organelles
Term
microtubules
Definition
alpha and beta tubulin dimers
-resist compression
-sort chromosomes during cell division
-movement of clia and flagella-alon with protein dynein
Term
Animals Extracellular Matrix
Definition
secreted by surrounding cells
-fiber is primarily collagen
-connect to fibronectins proteins
-connect to integral membrane protein-integrin
-integrin connect to actin portion of skeleton
Term
middle lamina
Definition
holds cell walls together in plants
Term
Cell to cell attachments in animals?
Definition
connection of ECM to cytoskeleton holds cells together
Term
tight junctions
Definition
protein adhesions that prevent materials from moving between cells
Term
tight junctions
Definition
protein adhesions that prevent materials from moving between cells
Term
Desmosomes
Definition
spot welds that hold cells together
-associate with intermediate filaments of cytoskeleton in cell.
-specific protein linkages=cadheins
-provide selective adhesion
-within cell many associate with
Term
Communication gaps
Definition
for coordinated cell function
Term
Plasmodesmata
Definition
-communication gap in plants
-plasma membranes of adjacent cells are continuous
-large things can pass
-have many protein regulators
Term
Gap Junctions
Definition
communication gaps in animals
-protein structure channels connect cell cytoplasm
-only small molecules or ions can pass
-(contraction coordination in cardiac muscle cells.
Term
Distant Cell Communication
Definition
message and response systems
-information regarding conditions
-regulation of homeostasis
-immune response
-maintenance of cycles
Term
Protein hormones
Definition
modified to glycoprotens
-travel through bloodstream and interstitial fluids.
Term
steroids
Definition
-synthesized from cholesterol
-can be carried by protein carriers in bloodstream or travel freely
Term
Receptors
Definition
proteins
-specific to the ligand
-numbers sometimes change in response to level of ligands
-receptors clicit cell response through variety of mechanisms = signal processing
-first change is conformational change in receptor protein
Term
signal processing of steroid hormones
Definition
-cross cell membrane
-intracellular receptor - cytosolic
-steroid binds to receptor -> conformational change
-ligand-receptor complex enters nucleus
-binds to DNA
-response is a change in gene activity
Term
Four steps of signal transduction
Definition
-reception
-processing (something is going to change the signal)
-response
-deactivation (stop the signal)
Term
Second messenger systems
Definition
-second messenger = nonprotein molecules inside cell
-in response to receptor conformation change, action higher [second messenger] and elicit respons
-often a cascade of events
-results in amplification of signal
Term
G-protein system
Definition
G-protein bound to inside face of membrane receptor
-activated by receptor conformational change
-binds to GTP
-G-protein splits and activated protion binds to enzyme
-enyme catalyzes reaction producing second messenger-a lot of it = amplification
-second messengers diffuse through cell and activate multiple cascades eliciting cell response
Term
Enzyme-Linked Receptors
Definition
receptor tyrosine kinases
-kinase = enzyme capable of phosphorylation when it becomes phosphorylated itself
-ligand binds to membrane receptor tyrosine kinase
-conformational change results in a kinase dimer
-ATP phosphorylates the kinase
-bridging protein binds Ras/GTP
-kinase then activates other proteins via phosphorylation
-phosphorylation events result in a string of activated enzymes activating more enzymes in a cascade of activation = amplification
Term
Signal Response
Definition
-receptor specific
-cell specific
Term
Signal Deactivation
Definition
-certain kinds of phosphorylation can deactivate stages in the cascade
-molecules of systems are often short lived
-enzymes may be present to break down molecules (phosphates can dephosphorylate)
-some signals are maintained for longer periods - some are brief
Term
Cross-Talk
Definition
synthesis of many signals-signal transduction pathways form networks of signals
-allows complex responses from same cell
---can be stimulation or inhibition
Term
Quorum Sensing in Bacteria
Definition
allows communication between individual cells of same species
-species specific
-colonies take on some characteristics of multi-cellular organism
-cells release signal molecules
Term
the hydrolysis of ATP is what kind of reaction?
Definition
Exergonic
Term
dehydration
Definition
removal of 2 H atoms (transferred to NAD+ and FAD)
Term
decarboxylation
Definition
part of a carboxyl group (-COOH) removed from substrate as CO2
Term
phosporlyation
Definition
phosphate transferred from one molecule to another
-to substrate (coupling endergonic ATP hydrolysis to reaction)
-phosphorylation of proteins causes conformational changes, activating or deactivating the protein.
Term
substrate-level phosphorylation
Definition
phosphate transferred from phosphorylated intermediate (substrate) to ADP to form ATP
Term
Oxidative phosphorylation
Definition
the production of ATP using a proton gradient as the source of energy to drive ATP synthase (the enzyme that catalyzes ADP +Pi ->ATP)
Term
aerobic
Definition
in the presence of oxygen
Term
Oxidative phosphorylation
Definition
the production of ATP using a proton gradient as the source of energy to drive ATP synthase (the enzyme that catalyzes ADP +Pi ->ATP)
Term
aerobic
Definition
in the presence of oxygen
Term
aerobic respiration
Definition
the process by which nutrients (carbohydrates and oxygen) plus water are catabolized (broken down) to carbon dioxide, water and energy (ATP)
Term
Glycolysis
Definition
first step in cellular respiration
-conversion of glucose (6 carbon) to pyruvate (3 carbon)
-ATP and NADH are formed
-does not need oxygen
-occurs in cytosol
Term
Where does Cellular Respiration occur?
Definition
mitochondria
Term
Pyruvate oxidation
Definition
formation of acetyl coenzyme A (acetyl coA)- each pyruvate is oxidized to acetate (2C) attached to coenzyme A, NADH is formed, CO2 is released.
Term
citric acid cycle (kreb's cylce)
Definition
- series of reaction in which acetate of acetyl coA is changed to carious carbon molecules releasing CO2 and forming ATP, NADH and FADH2
Term
Electron transport chain and chemiosmosis
Definition
process of removing electrons from NADH and FADH2 from above processes - energy from this is used to pump H (protons) across mitochodrial membrane to form proton gradient
Term
Summary of Pyruvate oxidation
Definition
-input: 2 pyruvate, 2 NAD+, 2 CoA
-yield: 2 acetyl CoA, 2NADH, 2 CO2
-net energy: 2 NADH
Term
summary of kreb's cycle
Definition
• Input
• Acetyl CoA (X2 = 2)
• 3 NAD+ (X2 = 6)
• FAD (X2 = 2)
• 2 H2O (X2 = 4) - IGNORE
• ADP (X2 = 2)

• Yield
• coenzyme A (X2 = 2)
• 2 CO2 (X2 = 4)
• 1 H2O (X2 = 2)- IGNORE
• 3NADH (X2 = 6)
• FADH2 (X2 = 2)
• ATP (X2 = 2)
• oxaloacetate for next cycle

• NET ENERGY (two cycles so, per glucose molecule)
• 6 NADH
• 2 FADH2
• 2 ATP
Term
Anaerobic respiration
Definition
-anaerobic bacteria
-terminal electron acceptor is nitrate or sulfate
Term
fermenation
Definition
-no electron transport chain
-2 ATPs produced from gylcolysis but cell risks losing supply of NAD+ with no transport chain.
Term
alcohol fermentation
Definition
-produces etyhl alcohol (basis for making beer, wine, etc.) and CO2
-yeasts are facultative anaerobes
Term
lactate fermentation
Definition
-produces lactate
-some bacteria (as in yogurt, sauerkraut)
-also fors in muscles when oxygen is used up
Term
Gametes
Definition
sperm and ova
Term
Somatic cells
Definition
rest of cells of an individual
Term
Mitosis
Definition
production of somatic cells
Term
Meiosis
Definition
production of gametes
Term
Genes
Definition
segments of DNA, each is a unit of hereditary information.
Term
karyotype
Definition
a count of the number and type of chromosomes an individual has
Term
G0 phase
Definition
period of no growth
Term
Interphase
Definition
-stage between cell divisions
-3 parts (G1 S and G2)
Term
G1 phase
Definition
-growth phase
-cell is undergoing routine metabolic activities
Term
S-phase
Definition
-period when DNA (chromosomes) is replicated in anticipation of cell division
-centrosomes also replicate = organelles involved in microtubule assemble
Term
G2 phase
Definition
increased protein synthesis in preparation for division
Term
Mitosis (M-phase)
Definition
nuclear division
-period when chromosomes are sorted and actual division occurs
-ends with cytokinesis
Term
centromes
Definition
consisted portion at center
Term
kenectochore
Definition
protein structure to which microtubules can attach
Term
Prophase
Definition
-nucleoli disappear
-chromatin fibers condense to chromatids (already replicated - S-phase)
-centrosomes move to opposite poles of cell
Term
Prometaphase
Definition
-nuclear membrane fragments
-miotic spindles form
-kinetochore microtubules form
Term
Metaphase
Definition
-nuclear membrane has disappeared
-kinetochore microtubules stretch from MCOT to chromatids (attach at kinetochore)
-chromosomes line up at equator, form metaphase plate
-sister chromatids face opposite poles of cell
Term
Anaphase
Definition
-sister chromatids are pulled apart
-one set of chromosomes moves to each pole of cell
Term
Telophase
Definition
-chromosomes have moved far apart
-nuclear membrane reassemble and two identical nuclei are formed
-cytoplasm begins to divide (cytokinesis) via constriction from contractile microfilaments
Term
cyclins
Definition
regulatory proteins that control protein kinases=phosphorylating enzymes
Term
cyclin dependent protein kinases
Definition
enzymes that only function when associated with cyclins (allosteric regulation)
Term
p53
Definition
prevents cycle from entering S-phase if DNA is damaged
-repairs of programs cell death (apoptosis)
Term
Retinoblastin Protein
Definition
blocks movement into S-phase
-normally bound to protein E2F
-GF, cyclin, Cdk complex allows phosphorylation of RB, removes E2F
-E2F stimulates proteins for DNA replication
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