Biology-Chapter 4 & 5 Flashcards
Cell Theory
States that all living things are composed of cells and that all cells come from earlier cells.
Prokaryotic Cells
Are found in organisms of the domains bacteria and Archaea, known as prokaryotes
Eukaryotic Cells
Organisms of the domain Eukarya- including protists, plants, fungi, and animals-are composed of this.
Plasma Membrane
All cells are bounded by this barrier, which regulates the traffic of molecules between the cell and its surroundings
Cytosol
Jellylike fluid, cellular components are suspended
Chromosomes
All cells have one or more of these, carrying genes made of DNA
Ribosomes
All cells have this, Build proteins according to the instructions from the genes
Name for structures found in both prokaryotic and Eukaryotic cells.
Plasma membrane, chromosomes, cytosol, and ribosomes
How is the nucleic region different from the nucleus of a eukaryotic cell?
There is no membrane enclosing the prokaryotic nucleoid region.
Organelles
Eukaryotic cells have this, Membrane enclosed structures that preform specific functions, and prokaryote cells do not.
Nucleus
Which houses most of a eukaryotic cell’s DNA, surrounded by a double membrane.
Nucleoid
A prokaryotic cell lacks a nucleus, its DNA is coiled into a nucleus like region
Cytoplasm
The region of the cell outside the nucleus and within the plasma membrane
Name three structures in plant cells that animal cells lack?
Chloroplasts, a central vacuole, and a cell wall
Name two structures that may be found in animal cells but not in plant cells
Centrioles and lysosomes
What polysaccharide is the primary component of plant cell walls?
Cellulose
What function does the organization of phospholipids into a bilayer in water serve?
The bilayer structure shields the hydrophobic tails of the phospholipids from water while exposing the hydrophilic heads to water.
Phospholipid Bilayer
Phospholipids grouped together to form a two layer sheet
Fluid Mosaic
Fluid because the molecules can move freely past one another and mosaic because o the diversity of the proteins that float like icebergs in the phospholipid sea.
Extracellular Matrix
Animal cells that lack a cell wall, but most animal cells secrete a sticky coat called this. Fibers made of the protein collagen hold cells together in tissues and can also have protective and supportive functions.
What is the relationship between chromosomes, chromatin, and DNA?
Chromosomes are made of chromatin, which is a combination of DNA and proteins.
Chromatin
Within the nucleus, long DNA molecules and associated proteins form fibers called this.
Nucleolus
A prominent structure within the nucleus, is the site where the components of ribosomes are made.
What is the function of ribosomes?
Protein synthesis
What is the role of mRNA in making a protein?
A molecule of mRNA carries the genetic message from a gene to ribosomes that translate into a protein.
Vesicles
Linked by this, transfer membrane segments between organelles
Endomembrane System
Includes the nuclear envelope, endoplasmic reticulum, the golgi apparatus, lysosomes, and vacules
Endoplasmic Reticulum
One of the main manufacturing facilities within a cells. Producess an enormous variety of molecules.
Rough ER
Refers to ribosomes that stud the outside of its membrane. Function is to make more membranes
Transport Vesicles
Sacs made of membrane that bud off from the rough ER
Smooth ER
Refers to the fact that this organelle lacks the ribosomes that populate the surface of rough ER
Golgi Apparatus
An organelle that receives, refines, stores, and distributes chemical products of the cell
What makes rough ER rough?
Ribosomes attached to the membrane
What is the relationship between the Golgi Apparatus and the ER in a protein-secreting cell?
The golgi apparatus receives proteins from the ER via vesicles, processes the proteins, and then dispatches them in vesicles
How can defective lysosomes result in excess accumulation of a particular chemical compound in a cell?
If the lysosome lack an enzyme needed to break down the compound, the cell will accumulate an excess of that compound.
Central Vacuole
A versatile compartment that can account for more than half the volume of a mature plant cell
Place the following cellular structures in the order they would be used in the production and secretion of a protein: Golgi apparatus, nucleus, plasma membrane, ribosome, transport vesicle.
Nucleus, ribosome, transport vesicle, Golgi apparatus, plasma membrane.
What does photosynthesis accomplish?
The conversion of light energy to chemical energy stored in food molecules
What is cellular respiration?
A process that converts the chemical energy of sugars and other food molecules to chemical energy in the form of ATP
Chloroplasts
Which are unique to photosynthetic cells of plants and algae, are the organelles that perform photosynthesis.
Mitochondria
Are the organelles in which cellular respiration takes place, during cellular respiration, energy is harvested from sugars and transformed into another form of chemical energy called ATP.
Cytoskeleton
A network of protein fibers extending throughout the cytoplasm. Serves as both a skeleton and muscles for the cell, functioning in support and movement.
Microtubules
Hollow tubes of protein
From which important class of biological molecules are the microtubules of the cytoskeleton made?
Protein
Compare and contrast cilia and flagella
Cilia and flagella have the same basic structure, are made from microtubules, and help move cells or move fluid over cells . Cilia are short and numerous and more back and forth. Flagella are longer, often occurring singly, and they undulate.
Cilia
Are generally shorter and more numerous than flagella and more in a coordinated back and forth motion.
Flagella
Propel cells with an undulating, whiplike motion.
Can an object at rest have energy ?
Yes, it can have potential energy because of its location or structure.
Which form of energy is most randomized and difficult to put to work?
Heat
Kinetic Energy
The energy of motion, Chemical energy from food is converted to this.
Conservation of energy
Explains that it is not possible to destroy or create energy.
Potential energy
The kinetic energy of muscle movement is stored as this, the energy an object has because of its location or structure.
Entropy
Is a measure of the amount of disorder, or randomness, in a system.
Heat
A type of kinetic energy contained in the random motion of atoms and molecules.
Chemical Energy
The molecules of food, gasoline, and other fuels have form of potential energy called this, which arises from the arrangement of atoms and can be released by a chemical reaction.
Calorie
The amount of energy that can raise the temperature of 1 gram of water by 1’c.
ATP
Consists of an organic molecule called adenosine plus a tail of three phosphate groups
Explain how ATP powers cellular work?
ATP transfers a phosphate to another molecule, increasing that molecules energy
What is the source of energy for regenerating ATP from ADP?
Chemical energy harvested from sugars and other organic fuels via cellular respiration
How does an enzyme affect the activation energy pf a chemical reaction?
An enzyme lowers the activation energy
Metabolism
The total of all the chemical reactions in an organism
Enzymes
Proteins that speed up chemical reactions without being consumed by those reactions.
Activation Energy
The energy that must be invested to start a reaction , it activates the reactants and triggers the chemical reaction
How does an enzyme recognize its substrate?
The substrate and the enzyme’s active site are complementary in shape and chemistry
Substrate
Selectivity is based on the enzymes ability to reorganize a certain reactant molecule which is called an enzymes substrate.
Induced fit
The entry of the substrate induces the enzyme to change shape slightly, making the fit between substrate and active site snugger.
Enzyme Inhibitors
Are substrate imposters that plug up the active site
Diffusion
The movement of molecules spreading out evenly into the available space.
What molecule is the usual energy source for active transport?
ATP
Exocytosis
During protein production by the cell, secretory proteins exit the cell from transport vesicles that fuse with the plasma membrane, spilling the contents outside the cell.
Endocytosis
A cell takes material in via vesicles that bud inward
Phagocytosis
Cellular eating, a cell engulfs a particle and packages it within a food vacuole
Active transport
Requires that a cell expends energy to move molecules across a membrane.
An animal cell shrivels when it is ___ compared with its environment?
Hypotonic
The cells of a wilted plant are__compared with their environments?
Isotonic
Osmoregulation
The control of water balance
Hypertonic
The solution with a higher concentration of solute is said to be this
Hypotonic
The solution with the lower solute concentration is said to be this.
Solute
A substance that is dissolved in a liquid solvent, and the resulting mixed is called a solution.
Osmosis
The diffusion of water across a selectively permeable membrane.
Facilitated diffusion
Substances that do not cross membranes spontaneously- or otherwise cross very slowly - can be transported via proteins that act as corridors for specific molecules. this assisted transport is called this.
Passive transport
The cell doesn’t expend any energy for the diffusion to happen. Ex: diffusion of dye across a membrane
Concentration gradient
In passive transport, a substance diffuses down its concentrated gradient , from where the substance is more concentrated to where it is less concentrated.
Why is facilitated diffusion a form of passive transport?
It uses proteins to transport materials down a concentration gradient without expending energy.
