Chapter 3 - Cells, Organelles, and Cellular Respiration Flashcards
the smallest unit of life
cells
what are prokaryotes?
o DNA dispersed in cell
o Very small
o Always single-celled
o Few organelles
what are eukaryotes?
o DNA in nucleus
o ~ 100 x Larger
o Often multicellular
o Many types of organelles
characteristics of a “typical” eukaryotic animal cell:
filled with fluids
immersed in a watery fluid
surrounded and linked to other cells
Animal Cells
everything going in and out of a cell must pass through the ___________
cell membrane
what is the size of a cell?
small in size because of surface to volume ratio (surface / volume)
6:1
major component made up of phopholipids
phospholipids bilayer
selectively permeable membrane encompassing cells
plasma membrane
what are the functions of the plasma membrane?
- Regulation of things going in and out of cell – ‘selectively permeable’
- Cell recognition
- Cell-cell communication
- Cell-cell adhesion
movement of solute from high to low concentrations
simple diffusion
movement of water from high to low concentration
osmosis
movement from high to low concentration using carrier proteins
facilitated diffusion
movement from low to high concentration. Requires pumps to use energy to move solute against the gradient
active transport
Bulk Transport:
movement of large molecules or large amounts of small molecules
endocytosis - Capturing bacteria in a vesicle, Phagocytosis = cell eating
Bulk Transport:
movement of large amounts of material out of cell – using a membrane bound ‘vesicles’
exocytosis - Grabbing on small things and bringing it in, Pinocytosis = cell drinking
Define organelles
structures inside of cells
List some organelles of interest:
Plasma Membrane Nucleus Rough Endoplasmic Reticulum Golgi Complex Lysosomes
contains most genetic information in cells, bound by nuclear envelope, produces RNA
nucleus
network of conduits connected to the nuclear envelop and studded with ribosomes
o Amino acids chains are assembled in ribosomes, then processed into proteins within the ER, and enclosed in vesicles for transfer
Rough Endoplasmic Reticulum
receives proteins, conducts further processing, sorting and packaging, FedEx
Golgi Complex
enzyme-filled vesicles that conduct intercellular digestion, enzymatic breakdown of worn out organelles, foreign invaders…
Lysosomes
List characteristics of Mitochondria:
• Structure where energy is extracted/capture from the breakdown of energy-rich molecules for use in cells
o 1st law of thermodynamics: energy can neither be created or destroyed but can be transferred
• Contains its own genetic information and ribosome
• Double membrane bound structure
• Contains its own genetic information and ribosomes
All of the structures in cytoskeleton are made predominately of _______
proteins
List how cells get energy from food
• Digest (breakdown) macromolecules from food into simpler components
▪ Example: complex carbohydrate
• Absorb simpler molecules into blood stream which carries them to cells where they may be further processed…
• Cells extract energy stored in the chemical bonds of energy-rich molecules, like simple sugars – Cellular Respiration
Ultimately, the energy used by the vast majority of organisms comes from the sun. Solar radiation.
What are these processes called?
photosynthesis
cellular respiration
process which plants (and some microorganisms) use to convert light energy into chemical energy that can later be released to fuel cellular activities
photosynthesis
process by which cells derive energy from the breakdown of energy-rich molecules, like glucose
cellular respiration
What is the formula for cellular respiration?
Glucose + Oxygen -> Energy + Carbon Dioxide + Water
Formula is exact opposite of photosynthesis.
List the three types of energy
Potential
Kinetic
Chemical
stored energy
potential
energy in motion
kinetic
energy stored in the bonds of chemical compounds
chemical
- Making ATP (from ADP and a P-group) takes energy
* Braking a P-group from ATP releases energy
Model of ATP function
cells acquire energy from the breakdown of energy-rich molecules, like glucose, to make ATP. ATP is used by cells to run the vast majority of biochemical machines that make life possible.
cellular respiration
formula of cellular respiration
Glucose + Oxygen -> (release of) Energy + Carbon Dioxide + Water
Glycolysis does not require _________
oxygen
Which parts of cellular respiration occurs in mitochondria and requires oxygen?
Transition reaction
Electron Transport Chain
Negative electrically charged subatomic particle
electron
Electrons carry ________
energy
_________ can be transferred among atoms and molecules
electrons
Electrons can transfer energy among atoms, molecules, and compounds
Very excited = high energy
Unexcited = low energy
What happens within glycolysis?
- Splitting requires 2 ATP to break glucose
- But makes 4 ATP (net gain 2 ATP)
- plus NADH (excited electrons) electron carrier molecule
- Splits glucose into two ‘Pyruvates’ (small sugars)
- Carbon dioxide lost as waste
NADH transfers energy from early steps in cellular respiration and provides it to the Electron Transport Chain
Electron carrier (NADH)
Electron carrier (NADH) • carries energy-rich electrons to ETC
▪ NAD+ accepts the electron from the hydrogen
▪ NAD then picks up another hydrogen becoming NADH
▪ NADH then, “drops off” its two excited electrons at the ETC
Transition Reaction (per Pyruvate) occurs in Mitochondria and produces what?
NADH (excited electrons)
What occurs in the Citric Acid Cycle?
completes breakdown of glucose
• Produces per turn (each Acetyl CoA):
2 CO2
1 ATP
NADH and FADH2 (excited electrons)
• After two turns (one for each pyruvate), all carbon from original glucose has been removed as waste but removed excited electrons
• 8 reactions each with its own specific enzyme
List the steps of cellular respiration
- Glycolysis
- Transition Reaction
- Citric Acid Cycle
- Electron Transport Chain
High energy electrons delivered by NADH and FADH2 are used in protein ________ to push H+ ions up gradient (from low to high concentration).
pumps
Electrons then flow down gradient through ATP Synthase to make ________
ATP
Low energy electrons eventually given to oxygen to make _______
ATP
An example of “intelligent design” ATP synthase must’ve been made by an intelligent being. This is an example of __________
pseudoscience
_________ is required for cellular respiration. Without it, there is nothing to accept the low energy electrons at end of ETC.
oxygen
• Without oxygen, there is no final electron receptor
• Electron shuttles cannot release their electrons
• Thus blocking ETC and CAC
• But energy can be “captured” when energy is lacking
Anaerobic respiration - breakdown of glucose without oxygen
• Glycolysis is modified
• Pyruvate (or a pyruvate derivative) accept the high energy electrons and produce lactic acid
• Net gain of 2 ATP
Fermentation
- Occurs in our muscles during strenuous exercises
- Oxygen in muscle cells runs low and cannot be replaced quickly enough
- Cells allow lactic acid fermentation to ensure continued production of some ATP
- Lactic acid builds up in muscles, then overtime need to be taken out and reprocessed
Lactic Acid Fermentation
Where did glucose come from?
photosynthesis
What is lactic acid fermentation associated with?
glycolysis, allows for some ATP to be produced even when oxygen is limited. Seen in muscle cells
Where is the most ATP made in the process of cellular respiration?
Electron Transport
Why doesn’t the citric acid cycle have an arrow to electron transport?
nothing goes that direction except excited electrons. All the carbon in the glucose molecule is used up and left as a waste product
Why is oxygen important in Cellular Respiration?
Uses oxygen to release energy to make ATP, which results in the waste products carbon dioxide and water
What require the process glycolysis to start?
Glycolysis requires 2 ATP to break down glucose
What is the waste product of cellular respiration?
water
