Lab 4 (chapter 4) Flashcards
What are the three major regions of a cell?
Plasma membrane, cytoplasm, and nucleus
What are the main components of the plasma membrane?
Phospholipids, proteins, and carbohydrates attached to some of the lipids and proteins.
What is selective permeability?
When some substances can pass through a membrane but not others
Define primary active transport
A carrier protein moves the solute through a membrane up (against) its concentration gradient. This process requires ATP from the cell.
Define passive transport
The movement of a molecule down its concentration gradient and across a membrane without the use of ATP
Define simple diffusion
The net movement of particles from place of high concentration to place of lower concentration
Define facilitated diffusion
A carrier protein moves the solute down its concentration gradient, and does not consume ATP
What’s the difference between simple diffusion and facilitated diffusion?
Facilitated diffusion requires a carrier protein
Define the nucleus
The “brain” of a cell
Define the nuclear envelope
A double membrane with pores surrounding the nucleus
Define nucleolus/ nucleoli
Masses where ribosomes are produced
Define chromatin
A thread-like substance composed of DNA and protein; one of two substances that makes up nucleoplasm
What’s the difference between cytoplasm and cytosol?
Cytoplasm contains the organelles; cytosol does not.
What is included in the cytoplasm?
–Organelles
–Cytoskeleton
–Inclusions (stored or foreign particles)
–Cytosol (intracellular fluid, ICF)
Define cytosol
The aqueous component of the cytoplasm of a cell
Which organelle is best described as system of channels (cisternae) enclosed by a membrane?
The endoplasmic reticulum
Which organelle is best described as parallel, flattened sacs covered with
ribosomes?
Rough ER
What does the rough ER do?
Protein synthesis and packages proteins for transport
What does the smooth ER do?
–Synthesizes steroids and other lipids
–Detoxifies alcohol and other drugs
–Calcium storage
What do ribosomes do?
They “read” coded genetic messages
(messenger RNA) and assemble amino acids
into proteins specified by the code
Which organelle is best described as small granules of protein and
RNA?
Ribosomes
What does the golgi complex do?
•Receives newly synthesized proteins from
rough ER
•Sorts proteins, modifies proteins, and
packages them into vesicles
–Some vesicles become lysosomes
–Some vesicles migrate to plasma membrane and fuse to it
–Some become secretory vesicles that store a protein product for later release
Which organelle is best described as an organelle
specialized for synthesizing ATP?
Mitochondria
What do mitochondria do?
They make ATP
What do centrioles do?
They form the mitotic spindle during cell division,
unpaired centrioles form basic structure of cilia and flagella
Which organelle is best described as a package of enzymes bound by a membrane?
Lysosomes
What do lysosomes do?
–Intracellular hydrolytic digestion
–Phagocytosis
–Autolysis
What do peroxisomes do?
Detoxify certain harmful chemicals, enclose
reactions that make toxic byproducts
What does the plasma membrane do?
•Defines cell boundaries
•Governs interactions with other cells
•Controls passage of materials in and out of
cell
Which organelle would best be described as the border of the cell (arranged in bilayer)?
Plasma membrane
