Ch:2 Cells Flashcards
What are the 3 Laws of Thermodynamics?
- Energy cannot be created or destroyed
- The entropy of the universe is continuously increasing
- No rxn is 100% efficient with some amount of energy lost as heat - As you reach absolute zero (0 kelvin), the entropy of the system is at a minimum
ATP allows ___ rxns to become _____.
Endergonic —> Exergonic
What is the difference between catabolism and anabolism?
Catabolism is breaking down of macro molecules into simple end products to extract it’s energy.
Anabolism is taking a small precursor and converting it to a larger more complex, which requires energy
If the OH on the anomeric carbon is pointing down it is considered ______.
Alpha
Alpha and beta SUGARS represent diastereomers called ______.
Anomers
Chitin is the main component in the cell wall of ______ and the exoskeleton of ________.
Fungi
Arthropods
What is the most abundant compound in the world that makes up the plant cell walls?
Cellulose
Glycogen is stored in the _____ and _____ _____.
Liver and skeletal muscles
Some prostaglandins enhance inflammation. What medication inhibit the work of an enzyme needed in the synthesis of prostaglandins?
Aspirin
Because of resonance, a peptide bond is about 40% double bond character. It is rigid, allowing ___little/alot___ of free rotation. We see a flat SP2 structure. Steric hinderance causes the trans conformation to be more stable than cis.
Little free rotation
“VERY IMPORTANT DAT CONCEPT”
What is the difference between the primary, secondary, tertiary and quaternary structures of proteins?
Primary structure: held by covalent bonds including disulfide bonds
Secondary structure: 3D conformation of localized regions held by hydrogen bonds (alpha helix and beta pleated sheets)
Tertiary structure: 3D shape of entire molecule held by all the bonds of previous structures plus salt bridges (electrostatic interactions) and hydrophobic interactions
Quaternary: Refers to the way one polypeptide chain interacts with another (hemoglobin)
What is the difference between the digestion and denaturation of a protein?
Digestion: lose primary structure (basically all)
Denaturation: lose all structures except primary
What is the difference between DNA and RNA?
DNA is double stranded and resides exclusively in the nucleus
RNA is single stranded and can leave the nucleus and direct the synthesis of proteins in ribosomes
What is the monomer of nucleic acids?
Nucleotides
What is the difference between a nucleotide and nucleoside?
Nucleotide: sugar, phosphate, N-base
Nucleoside: sugar, N-base
(Nucleosides lack phosphate)
What is the difference between purines and pyrimidines and give examples of only purines:
What combination of purine and pyrimidine has 3 H-bonds?
Purines have 2 rings and pyrimidines only have one
Purines: A and G
3 H-bonds: G-C
What forms the structural framework of DNA and RNA?
Sugar-phosphate “backbone”
“KNOW THAT FOR THE DAT, YOU WILL THANK ME”
The connection between successive monomer units in nucleic acids is the ________ _____. It is between the #-OH of one sugar and #-OH of another sugar.
phosphodiester link: connection between monomer units in nucleic acids
3’-OH and 5’-OH
In the plasma membrane the ____ heads and ____ tails of the phospholipid bilayer is considered amphipathic.
Hydrophilic heads
Hydrophobic tails
What is the fluid mosaic model?
Lipids and many proteins are in constant lateral motion.
Talks about the plasma membrane and how peripheral and integral proteins float in this layer like an iceberg.
When you see fuzzy stuff looking through a microscope, what type of microscope are you looking through?
Transmission Electron Microscope
“DK DAT”
What is the difference between phagocytosis and pinocytosis?
Phagocytosis is cell “eating”
Pinocytosis is cell “drinking”
What is a major player in cell-mediated endocytosis?
Clathrin
Give an example of exocytosis:
Beta cells in the pancreas make insulin and secrete it into the blood by exocytosis
What part of mitochondria does the electron transport chain occur?
Inner mitochondrial membrane
What process produces 90% of the ATP produced in cells?
ETC (electron transport chain)
Do lysosomes have a membrane?
Yes
What is the duty of lysosomes?
digest macromolecules
Which 2 WBCs are loaded with lysosomes?
Neutrophils and Macrophages
“KNOW THIS FOR THE DAT, YOU MAY THANK ME ONE DAY”
The Golgi apparatus receives its materials from ____.
Endoplasmic reticulum
What is the duty of the Golgi apparatus?
The golgi is like a “warehouse”, sorting and shipping
- involved in the synthesis of carbs and modification of proteins
How are lysosomes formed?
budding from the golgi
What is the difference between the rough ER and smooth ER?
Rough ER: makes proteins
Smooth ER: Makes lipids and steroids
Which organs are abundant in smooth ER?
Liver
The smooth ER in the liver contains a large amount of cytochrome 450 and participates in detoxifying drugs
Part of the Rough ER is continuous with the ______ ____.
Nuclear envelope
Where are ribosomes synthesized?
Nucleolus
Which organelle lacks a membrane?
A. Nucleus
B. Mitochondria
C. Nucleolus
D. Endoplasmic Reticulum
C. Nucleolus
What is the difference between heterochromatin and euchromatin?
heterochromatin is dense and found near the nuclear envelope. (dense so NOT actively transcribing) (DARK)
euchromatin is the light area, less dense and actively transcribing
What 2 cells in humans lack a nucleus?
RBCs and platelets
What is the duty of a proteasome?
They degrade unneeded proteins
“quality control protein department”
What are each stack of thylakoids referred to as?
Grana
Tell me about chloroplast:
- Site of photosynthesis
- Contains chlorophyll
- Contains stacks of thylakoids called grana
- like mitochondria they have their own DNA
What are cilia and flagella composed of?
Microtubules
What are molecular motors and give examples of molecular motors:
Molecular motors are enzymes that will “walk” along microtubules
The molecular motors include dyneins and Kinesins.
“FAVORITE DAT QUESTION-TYPE”
Rank these in order from largest to smallest:
- Microtubules
- Microfilaments
- Intermediate filaments
Microtubules > Intermediate filaments > Microfilaments
Tell me about microfilaments:
- Built from actin
- Like the motor protein dynein, myosin is another motor protein that loves to “walk” but it is microfilament based and not microtubule based like dynein
What is the pattern of cilia and flagella?
9+2 pattern and is called axoneme
“A SURE BET TO APPEAR ON THE DAT!!!”
Tell me about intermediate filaments:
Anchor the nucleus and provide structural support for the cell
Keratins represent a predominant type of intermediate fiber.
What is the duty of Keratin?
Keratins provide protection against abrasion and prevent water loss in epidermal cells
“A MUST HAVE FOR THE DAT!”
What make up centrosomes?
a pair of perpendicular centrioles
Centrioles are found in animal cells and NOT ____.
Plant cells
What is the role of centrioles during cell division?
Centrioles move to opposite ends of the cell. Microtubules extend from the centrioles a to form the spindle. Some of the microtubules attach to the chromosome by connecting to protein complexes called Kinetochores.
What is the difference between gap junctions and tight junctions?
Gap junctions: allows communication between cells (pores)
- proteins of gap junctions are called *connexins”
- Responsible for the heart’s coordinate beat
Tight junctions: forms seal around cell to prevent leaking
- intestinal barrier is maintained by tight junctions
What is the difference between desmosomes and plasodesmata?
Desmosomes are like “staples” that connect cells together
- have intermediate filaments that are strong, they are common in epithelia that need to withstand abrasion such as the skin
Plasmodesmata: intercellular channels that connect *plant” cells
