Quiz 2 Chap 4&5 Flashcards
important figures in magnifying technology and what they created
Robert Hooke - early compound scope (magnifying glass)
Antonie van Leeuwenhoek - first dissecting microscope
3 components of Cell Theory
- all living organisms are made of cells
- cells are the basic units of life
- all cells come from pre-existing cells that have multiplied
types of prokaryotic cells
bacteria and archaea
types of eukaryotic cells
protists, fungi, plants, animals
basic features of all cells
- plasma membrane with semifluid cytosol
- chromosomes (genes)
- ribosomes (make proteins)
features of prokaryotic cells
- no nucleus
- DNA in unbound region (nucleoid)
- no membrane-bound organelles
- cytoplasm bound by plasma membrane
features of eukaryotic cells
- membrane-bound nucleus (DNA) and organelles
- cytoplasm between plasma membrane and nucleus
- much larger than prokaryotic cells
challenges all eukaryotic cells experience
- nutrition
- excretion
- energy
- interaction with environment
- reproduction
what limits cell size?
SA/volume ratio
- as surface area increases by n squared, volume increases by n cubed
- small cells have a greater surface area relative to volume
difference between plant and animal cells
animals: just semifluid membrane
plants: cell membrane and wall, more rigid
- chloroplasts
- large central vacuole
endomembrane system
complex and dynamic compartmental cell organization
- regulates protein traffic
- performs metabolic functions
- components either continuous or connected via transfer by vesicles
parts of the endomembrane system
plasma membrane nuclear envelope endoplasmic reticulum golgi apparatus lysosomes vacuoles
plasma membrane
selective barrier to cell allowing for the passage of oxygen and nutrients
- basic structure is a phospholipid bilayer
- proteins allow for membrane transport, often active
nucleus
- largest organelle, most of cell’s DNA
- shape maintained by nuclear lamina
nuclear envelope
double membrane around nucleus (2 bilayers)
- pores regulate entry and exit of materials from the nucleus
chromatin
genetic material in nucleus (DNA and proteins), condenses into chromosomes during prophase I
nucleolus
site of ribosomal RNA synthesis
endoplasmic reticulum
more than 50% of membrane in cell, continuous with nuclear envelope
smooth ER
no ribosomes
- synthesizes lipids
- metabolizes carbs
- detoxifies posions
- stores calcium
rough ER
bound ribosomes on surface
- secretes glycoproteins (proteins bound to carbs covalently)
- distributes transport vesicles
- membrane factory for cell
golgi apparatus STRUCTURE and function
flattened membrane sacs “cisternae”
- modifies ER products and sorts material into transport vesicle
- manufactures certain macromolecules
lysosomes
digestive compartments
- membranous sac of hydrolytic enzymes that digest
macromolecules (hydrolize proteins, fats,
polysaccharaides, and nucleus acids)
- conduct autophagy – recycle the cell’s own
organelles and macromolecules
phagocytosis
(when cells absorb bacteria/other material): lysosomes fuse with food vacuole to digest molecules
types and functions of vacuoles
food vacuoles (animals) -- break down macromolecules contractile vacuoles (protists) -- pump excess water out of cells to help movement central vacuoles (plants) -- hold organic compounds and water
structure and functions of cytoskeleton
network of fibers (actin, myosin, dyenin) in cytoplasm
- organizes cell shape, structure, and activities
- anchors organelles
- interacts with motor proteins
- aligns chromosomes during cell division
importance of mitochondria structure
double membrane, smooth outer and folded inner (cristae)
- not connected to endomembrane system
- increases SA for ATP synthesis
- inner membrane separates intermembrane space and matrix
- some steps of respiration catalyzed in matrix
mitochondria function
change energy from one form to another
- cellular respiration, generates ATP
metabolism
all of organism’s chemical reactions, emergent properties arise from interactions between molecules within cell
metabolic pathway
linked series of chemical reactions
- begins with a specific molecule and ends with a product
- each step catalyzed by a specific enzyme
anabolic vs catabolic pathways
anabolic - build large molecules (i.e. protein synthesis)
catabolic - releases energy by breaking down complex molecules (respiration)
ATP structure and what is it
cell’s energy shuttle
- made of ribose (sugar), adenine (nitrogenous base), and 3 phosphate groups
how does ATP function in the cell
- energy released when phosphate bonds broken by hydrolysis
- ATP regenerated by an addition of a phosphate group to ADP
phosphorylation
chemical addition of a phosphate group
- phosphorylation cascade of proteins (signal transduction)
- oxidative phosphorylation of ATP (cellular respiration)
enzymes
catalytic proteins that speed up reactions by lowering activation energy
catalyst
chemical agent that speeds up a reaction without being consumed
activation energy
initial energy needed to start a chemical reaction, often supplied as heat from surroundings
**enzymes lower activation energy
aerobic vs anaerobic respiration
aerobic: consumes organic molecules and O2, yields ATP
anaerobic: consumes compounds other than O2
what is the fuel for respiration?
primarily glucose, but carbs, fats, and proteins can all power it
redox reactions
chemical reactions that transfer electrons between reactants
- release energy used to synthesize ATP
oxidation vs reduction
oxidation - substance loses electrons, is oxidized, is reducing agent
reduction - substance gains electrons, is reduced, is oxidizing agent
what is oxidized during cellular respiration? what is reduced?
- fuel (glucose) is oxidized
- carriers like NADH are temporarily reduced, then oxidized in ETC
- O2 is reduced (at the end of ETC to form H2O)
how do electrons transfer energy in respiration?
- electrons from organic compounds first transferred to NAD+ to make NADH
and also to coenzyme A - each NADH represents stored energy to make ATP
- NADH “electron carriers” donate electrons to compounds during the Electron
Transport Chain- in ETC, O2 pulls electrons down the chain yielding energy for ATP in a series of redox reactions
4 stages of respiration
glycolysis (glucose –> pyruvate)
pyruvate oxidation
citric acid cycle (completes glucose breakdown)
oxidative phosphorylation (most of ATP synthesis)
what stages does most ATP come from?
- 90% produced during oxidative phosphorylation, powered by
redox reactions - rest produced during glycolysis and citric acid cycle by
substrate-level phosphorylation
glycolysis – where, what goes in, what comes out
occurs in the cytoplasm; 2 major phases
- energy investment phase (-2 ATP)
*ATP used in phosphorylation of glucose, then split into 2 3-
carbon molecules - energy payoff phase (+4 ATP, +2 NADH)
* phosphorylation without ATP investment
* net gain of +2 ATP and +2 NADH
pyruvate oxidation – where, what goes in, what comes out
occurs in matrix–pyruvate (3 carbon) binds with coenzyme A to become Acetyl CoA
citric acid cycle – where, what goes in, what comes out
oxidizes pyruvate within mitochondrial matrix; 8 steps each catalyzed by a specific enzyme
***begins with Acetyl CoA, yields 1 ATP, 3 NADH, and 1 FADH2
per turn
- acetyl group of Acetyl CoA joins the cycle by binding with
oxaloacetate to become citrate - next 7 steps decompose citrate back to oxaloacetate (making a
cycle) - NADH and FADH2 that are produced by the cycle relay
electrons from pyruvate to the ETC
