Nucleus, DNA, Chromosomes Vocabulary with definitions
You have a 2-kg bottle of liquid water at 0°C. About how many Calories are needed to heat up the water to 100°C?
200 Calories —remember...food calories = kilocalories so 1 food "Calorie" = raise 1 kg 1 degree Kapital C = Kilocalorie
Eggs = 75 calories. Running burns approximately 600 Calories per hour. If you ate four hard-boiled eggs, how long would you have to run to burn them off?
30 minutes
An enzyme speeds up reactions by lowering the __________.
Activation Energy
An enzyme is specific because the shape of its __________ matches only particular reactants.
Active Site
What evidence suggests that mitochondria might have evolved before chloroplasts?
Almost all eukaryotes have mitochondria but only some cells have chloroplasts.
An enzyme is considered a(n) __________ because it speeds up a chemical reaction without being used up.
Catalyst
Which theory states that all living things are composed of cells?
Cell Theory
What characteristic of chloroplasts that suggests that they might have evolved from free-living bacteria?
Chloroplasts have their own DNA.
__________ are tightly coiled bundles of DNA and protein found in the nucleus of most living cells.
Chromosomes
A(n) __________ , which is often a vitamin, binds to an enzyme and plays a role in catalysis.
Coenzyme
__________ is the self-replicating material present in nearly all living organisms; it is the main constituent of chromosomes and the carrier of genetic information.
DNA
High temperatures or changes in pH can __________ an enzyme, causing it to lose its shape and biological activity.
Denature
The endomembrane system includes _______________________________.
Golgi apparatus, lysosomes, vacuoles, and the endoplasmic reticulum
A plant cell placed in a(n) __________ solution will lose water and plasmolyze.
Hypertonic
There is a net diffusion of water out of an animal cell when it is placed in a(n) __________ solution.
Hypertonic
An animal cell placed in a(n) __________ solution will gain water, swell, and possibly burst.
Hypotonic
The ideal osmotic environment for a plant cell is a(n) __________ environment.
Hypotonic
The __________ between an active site and its substrate often strains bonds and helps the reaction proceed.
Induced Fit
A plant cell surrounded by a(n) __________ solution will be flaccid (limp).
Isotonic
The ideal osmotic environment for an animal cell is a(n) __________ environment.
Isotonic
You are riding on your bike and stop pedaling, coasting along the road. Eventually, your bike slows down and stops. What happened to the energy of your motion when your bike stopped?
It was released as heat.
Which of the following is a characteristic of mitochondria that suggests that they might have evolved from free-living bacteria?
Mitochondria have their own DNA
A protein-lined channel in the nuclear envelope that regulates the transportation of molecules between the nucleus and the cytoplasm is called a __________.
Nuclear Pore
Which molecules spontaneously form membranes when mixed in water and most likely were one of the first organic compounds formed on Earth?
Phospholipids
___________ are the major lipids of plasma membranes.
Phospholipids
What term that starts with the letter "p" is a feature of prokaryotic cells but not eukaryotic cells?
Pili
When using a microscope to view cells you obtained from scraping under your fingernails, you notice that the cells lack nuclei; therefore, you conclude that the cells must be a type of ___________ cell.
Prokaryotic
__________ is used in all steps of protein synthesis and carries the genetic information of many viruses.
RNA
In a catalyzed reaction, a reactant is often called a(n) __________
Sunstrate
Glucose molecules provide energy to power the swimming motion of sperm. In this example, the sperm are changing ___________.
chemical energy into kinetic energy
What is the term for the a measure of randomness in a system?
entropy
If a person eats one hard-boiled egg and digests the egg fully, cellular respiration will convert most of this energy into ________.
heat
A rock on the top of a mountain contains __________ energy.
potential
___________ is a function of the Golgi apparatus?
protein modification
Cells in the thyroid gland produce and secrete thyroid hormone (a polymer of amino acids) that helps to regulate metabolism. What organelle is most likely abundant in cells of the thyroid gland?
rough endoplasmic reticulum
Cellular respiration can be described as the conversion of the energy _______________________________.
stored in food molecules to energy stored in ATP
Which component of the following reaction is the substrate? sucrose + sucrase + water → sucrase + glucose + fructose
sucrose —substrate = -OSE
___________________ is an adaptation to increase the surface area of a part of a cell that is involved in cellular respiration?
the cristae of a mitochondrion
Most human cells contain __________ chromosomes.
—46 (23 pair)
___________ store the information necessary to produce proteins.
—Genes
Plants are susceptible to bacterial infections, which can damage their structure or even kill them. What would be the best antibiotic to treat a plant that is infected with bacteria?
—a drug that blocks gene expression in circular chromosomes
Some ribosomes are suspended in the cytosol of a cell, whereas other ribosomes __________.
—are attached to the outside of the nucleus
When mixed with water, phospholipids spontaneously form membranes because they ___________.
—have hydrophilic phosphate groups that are attracted to water and hydrophobic fatty acid tails that avoid water
One difference between eukaryotic and prokaryotic cells is that eukaryotic cells _______________________________ prokaryotic cells.
—have membrane-enclosed structures called organelles, which are lacking in
Nucleus
—most prominent membrane-bound organelle in eukaryotic cells —houses most of a cell's DNA.
Which structure manufactures the components of ribosomes?
—nucleolus
The concept of a membrane as a fluid mosaic reflects the ability of ___________.
—phospholipids and most proteins to drift about in the plane of the membrane
Nucleolus (little nucleus)
—round body inside the nucleus of a eukaryotic cell that makes ribosomal subunits from proteins and ribosomal RNA.
Which part of a cell is (are) most like the shipping center of a company?
—the Golgi apparatus
Nuclear Envelope
—two-layered membrane that encases the nucleus of a eukaryotic cell —separates the nucleus from the cytoplasm.