Cell Structure & Function
Ribosomes function and location:
Synthesize proteins
Rough ER and cytoplasm
Synthesizes proteins according to mRNA sequences
What are ribosomes?
Cholesterol’s role in phospholipid bilayer
Keeps phospholipids fluid and moving
Which statement best describes the structure of the plasma membrane?
A. A layer of proteins surrounding a carbohydrate layer
B. A phospholipid bilayer with embedded proteins
C. A carbohydrate bilayer surrounded by proteins
D. A single layer of phospholipids
B
What is passive transport?
Movement of substances across the membrane without using cellular energy (ATP).
What is the function of the Rough and Smooth ER
Smooth: Synthesizes lipids and carbs as well as detoxification
Rough: Ribosomes attached synthesize proteins, and sends to golgi for modification
What is the function of Vacuoles
Stores: water, salt, carbs, proteins
Membrane-enclosed sacs found in some eukaryotic cells that contain hydrolytic enzymes.
What are lysosomes?
What is active transport?
Movement of substances against their concentration gradient using energy, usually ATP.
Movement of ions against a concentration gradient, requiring energy.
Active Transport
Where does the Golgi send the modified proteins?
Lysosomes
Plasma membrane
Outside the cell (hormone secretion)
A cell is placed in a solution with a lower solute concentration than the cell. What will most likely happen?
A. Water leaves the cell
B. Water enters the cell
C. Solute leaves the cell
D. No net movement of water occurs
(Include hypo, hyper, isotonic, no change in your answer)
B — Water enters the cell
The surrounding solution is hypotonic, so water moves into the cell by osmosis.
What organelle has a compartment filled with very acidic inner fluid
Lysosomes
Describe selective permeability
-direct consequence of fluid membrane structure
-lets certain things in, but not others
-Yes: small, nonpolar molecules & some small polar molecules (water)
-No: larger nonpolar & polar molecules
Movement of small nonpolar molecules across a cell membrane.
What is simple diffusion?
Animal vs. Plant Cells
-Animal: no chloroplasts, no cell wall, shrivel when hypertonic
-Plant: larger vacuoles, more square in shape due to cell wall
This organelle:
-double membrane
-inner folds, cristae
-site of electron transport & ATP synthesis (respiration)
What is the mitochondria?
This organelle is responsible for making and transporting proteins.
What is the rough endoplasmic reticulum?
What is it called in regard to the regulation of the movement of water into and out of cells.
osmoregulation
The movement of molecules from high to low concentration across a cell membrane using a protein channel.
facilitated diffusion
Prokaryotic vs. Eukaryotic cells
-Prok: no (true) nucleus, no organelles, all have cell walls,
-Euk: nucleus, organelles, no cell walls in vertebrates
-Both: genetic material & ribosomes
This organelle:
-double membrane
-thylakoids, stroma, granum
-site of light-dependent rxns (photosynthesis)
-convert light into sugars (glucose)
-only in plant cells
What is the chloroplast?
Why is compartmentalization important in eukaryotic cells?
-minimizes competing rxns
-increases surface area
-overall increase in efficiency
What are membrane proteins used for?
They can function in transport, cell signaling, recognition, adhesion, and enzymatic activity
What happens to an animal cell in a hypertonic solution?
Water leaves the cell, causing it to shrink.