Ch. 3 Cells (Exam 1) Flashcards
What are the 3 main components of the lipid bilayer?
1) Phospholipids
2) Glycolipids
3) Cholesterol
What is the difference between channel and carrier proteins?
Channel - forms hydrophilic pores in membrane to facultatively diffuse molecules down the concentration gradient
Carrier - bind and physically move substances up and down the concentration gradient
What is the function of a glycoprotein?
Cell-to-cell recognition e.g. for organ/tissue rejection
Law stating that molecules move from an area of greater to lesser concentration until equally distributed.
What is the law of diffusion?
What 5 factors affect the rate of diffusion?
1) Concentration gradient
2) Size
3) Shape
4) Polarity
5) Temperature
The net movement of water molecules from a greater to lesser water concentration region.
What is osmosis?
Define isotonicity, hypertonicity, and hypotonicity.
Isotonicity - same concentration of solutes and fluid inside and outside of the cell
Hypertonicity - greater concentration of solutes than fluid outside of the cell
Hypotonicity - lesser concentration of solutes than fluid outside of the cell
What is the difference between passive and active transport in terms of the concentration gradient?
Passive - goes w/ concentration gradient
Active - goes against concentration gradient
The Na/K/ATPase pump utilizes { } transport and contributes to maintaining the cell membrane { }.
1) Active
2) Potential
What is the ratio of K moved in to Na moved out via the Na/K pump?
2 K in to 3 Na out
What is the purpose of bulk transport?
To move large molecules or quantities across the cell membrane
What is the difference between phagocytosis and receptor-mediated endocytosis?
Phagocytosis - nonspecific intake of food particles
Receptor-mediated endocytosis - very specific; uses special receptor proteins to carry large particles across cell membrane
Exocytosis secretes materials using the { } apparatus.
Golgi
Meaning self-eating, an intracellular degradation system wherein organic material is recycled into small monomers.
What is autophagy?
Which organelle is responsible for autophagy?
Lysosome
What are the 4 components of the nucleus?
1) Bilayered nuclear envelope
2) Pores
3) Chromatin
4) Nucleolus
What is the purpose of the nuclear envelope?
To separate nuclear contents from cytoplasm
What is the purpose of nuclear pores?
To regulate the passage of mRNA since DNA is too big to pass through
What is the purpose of chromatin?
To wrap DNA around histones to fit in the nucleus
What is the purpose of the nucleolus?
Site of ribosome synthesis
What are the 2 types of ribosomes and their purposes?
Free - make proteins for cell
Attached - make proteins to be used by other cells
Name 1 function of the smooth ER.
Make liver enzymes to detox blood (within hepatocytes)
What is the main difference in function between the rough and smooth ER?
Rough ER has the same function across all cells while smooth ER has different functions across different cells
Under what condition will ribosomes attach to the rough ER membrane?
If the 20 amino acid signal sequence is present on the ribosome
What is the function of the Golgi apparatus?
Packaging and distribution
What are the 2 faces of the Golgi apparatus, along with their functions?
Cis - receives & chemically modifies proteins (cleaving amino acids or adding carb chains)
Trans - Packages protein in vesicles for exocytosis
Lysosomes are vesicles formed by the { } apparatus and contain { } enzymes.
1) Golgi
2) Hydrolytic
The site of cellular respiration.
What are mitochondria?
What makes the mitochondria so unique?
It is a semiautonomous organelle with its own genome and is enveloped in a double membrane bilayer
What is the purpose of cristae in mitochondria?
To increase surface area
The cytoskeleton consists of thin { } radiating from the nucleus to the plasma membrane.
Proteins
Name 3 structural components of the cytoskeleton.
1) Microtubules
2) Microfilaments
3) Intermediate filaments
What is the purpose of the cytoskeleton?
To serve as a network for maintaining cell shape/movement
Centrosomes are paired clusters of { } generating spindle organization in { }.
1) Centroids
2) Cell division
These small, hairlike structures are numerous and help filter out bad particles from the respiratory tract.
What are cilia?
Cilia are useful because they increase the {
} of the cell membrane.
Surface area
How are flagella useful to sperm cells?
They provide movement
Little shaggy hairs found in the kidney tubules.
What are microvilli?
Why are microvilli important in general?
To increase surface area for optimal absorption
Why are microvilli important to the kidney tubules?
The sheer amount of fluid that needs filtering requires the kidneys to have adequate surface area
Process by which DNA is transcribed to RNA and then translated to protein.
What is protein synthesis?
Sequence of nucleotides that generates a unique polypeptide.
What is a gene?
3 nucleotides code for 1 { }.
Amino acid
Which type of RNA takes place in transcription?
Messenger RNA (mRNA)
What are the 2 key steps in transcription?
1) mRNA from DNA
2) mRNA travels from nucleus to ribosome
Name the 3 stages of translation.
1) Initiation
2) Elongation
3) Termination
Describe translation in a raunchy way using these 5 analogies:
1) Ribosome is the pimp
2) mRNA is the money
3) tRNA is the hoe
4) Amino acids are gold
5) Polypeptides are the gold reserve
The pimp (ribosome) counts the money (3 bases at a time i.e. codon). The hoe (tRNA) brings the pimp an item of equal value per 3 nucleotide bases. This item (amino acid) is a gold brick. Each money set is different, so the hoe brings a differently labeled brick every time. These bricks add up to make a gold-backed reserve (polypeptide).
Name 2 ways attachment proteins form connections.
1) Cell to cell
2) Cell to extracellular matrix
Name 2 examples of attachment proteins.
Cadherins & integrins
