Exam 1 Study Guide Ch. 3 Flashcards
What is the composition of the plasma membrane?
a phospholipid bilayer with embedded proteins arranged as a fluid mosaic. consists of lipids, proteins, and carbohydrates
What are active transport processes?
Occur when a cell uses energy to move solutes across the membrane; move solutes “uphill” against the conc. gradient
-ex: sodium potassium pump
What are passive transport processes?
move from high to low conc. w their gradient
-simple diffusion
-facilitated diffusion
-osmosis
What is endocytosis?
vesicles bringing bulk materials into the cell
-phagocytosis
-pinocytosis
-receptor mediated endocytosis
What is exocytosis?
vesicular transport processes that eject substances from cell; secretion
What is the resting membrane potential? Is it active or passive?
produced by separation of oppositely charged particles across membrane in cells
-cells described as polarized
-passive
What is the function of the mitochondria?
produces ATP for cellular energy
What is the function of ribosomes?
site of protein synthesis
What is the function of the endoplasmic reticulum?
Rough ER is used for storage and transport of proteins. Smooth ER is the site of steroid and lipid synthesis.
What is the function of the Golgi apparatus?
packages proteins or other substances for export from cell or incorporation in plasma membrane
What is the function of a lysosome?
to digest worn out cell organelles and foreign substances
What is the function of a peroxisome?
contain oxidase enzyme that detoxify alcohol, free radicals, and other harmful chemicals
Compare the functions of lysosomes and peroxisomes.
Lysosomes are responsible for the digestion of cells, while peroxisomes are responsible for the protection of cells against hydrogen peroxide.
What are the cytoskeletal elements? What do they do?
Microfilaments: important in cell mobility, particularly in muscle cells
Intermediate Filaments: stable elements composed of a variety of proteins and resist mechanical forces acting on cell
Microtubules: form the internal structure of the centrioles and help determine cell shape
What are the phases of the cell cycle?
- Interphase
-G1, S, G2 - Prophase
- Metaphase
- Anaphase
- Telophase
Cytokinesis
When is cell division complete?
Cytokineses
What is a gene?
A sequence of DNA that encodes a protein
What is the genetic code?
The rules by which the base sequence of a gene is translated into an amino acid sequence.
What is translation?
the process in which genetic information carried by an mRNA molecule is decoded in the ribosome to form a particular polypeptide.
What is transcription?
transfers information from a DNA base sequence to the complementary base sequence of an mRNA molecule.
What are triplets?
Each sequence of three bases is called a triplet. The sequence of triplets in each gene forms a sentence that tells exactly how a particular polypeptide is meant to be. Ex: AAA
What are codons?
The corresponding three base sequence on mRNA for each triplet.
