Bio Midterm Flashcards
Explain the scientific method
a researcher develops a hypothesis, tests it through various means, and then modifies the hypothesis on the basis of the outcome of the tests and experiments
What is the difference between an independent and dependent variable?
Independent variables are what we expect will influence dependent variables. A Dependent variable is what happens as a result of the independent variable.
what is the difference between quantitative data and qualitative data?
Quantitative data refers to any information that can be quantified, counted or measured, and given a numerical value. Qualitative data is descriptive in nature, expressed in terms of language rather than numerical values.
8 characteristics of living organisms
reaction, reproduction, evolution, regulation, homeostasis, and ability to create energy, at least 1 cell
What is the difference between an autotroph and a heterotroph?
Autotrophs are known as producers because they are able to make their own food from raw materials and energy. Examples include plants, algae, and some types of bacteria. Heterotrophs are known as consumers because they consume producers or other consumers.
6 elements in organic compounds? what is the acronym?
The acronym CHNOPS, which stands for carbon, hydrogen, nitrogen, oxygen, phosphorus, sulfur, represents the six most important chemical elements whose covalent combinations make up most biological molecules on Earth.
what is the main function of each group of organic compound?
The carbohydrates are quick energy storage
The lipids are used to store energy for later usage.
The proteins are used to control the energy created
Give examples of molecules from each group of organic molecules.
Examples of organic
What are four classes of organic molecules?
There are four classes of organic molecules: carbohydrates, lipids, proteins, and nucleic acids
how do enzymes affect chemical reactions?
Enzymes in our bodies are catalysts that speed up reactions by helping to lower the activation energy needed to start a reaction.
Define catalyst..
A catalyst is a substance that speeds up a chemical reaction, or lowers the temperature or pressure needed to start one, without itself being consumed during the reaction. Catalysis is the process of adding a catalyst to facilitate a reaction
how do factors such as enzyme concentration affect enzyme activity?
Enzyme concentration: Increasing enzyme concentration will speed up the reaction, as long as there is substrate available to bind to.
how do factors such as temperature and pH affect enzyme activity?
Temperature: Raising temperature generally speeds up a reaction, and lowering temperature slows down a reaction. However, extreme high temperatures can cause an enzyme to lose its shape (denature) and stop working. pH: Each enzyme has an optimum pH range. Changing the pH outside of this range will slow enzyme activity
Describe contributions of scientists to the development of cell theory
Credit for developing cell theory is usually given to three scientists: Theodor Schwann, Matthias Jakob Schleiden, and Rudolf Virchow. In 1839, Schwann and Schleiden suggested that cells were the basic unit of life. Their theory accepted the first two tenets of modern cell theory
List the 3 parts of cell theory
The three parts of the cell theory are:
All living things are composed of cells.
Cells are the basic units of structure and function for living things.
All cells come from pre-existing cells. Also, organisms grow by “adding on more cells” NOT by increasing the size of their cells.
Difference between prokaryotic cells and eukaryotic cells?
Prokaryotes are always unicellular, while eukaryotes are often multi-celled organisms. Additionally, eukaryotic cells are more than 100 to 10,000 times larger than prokaryotic cells and are much more complex. The DNA in eukaryotes is stored within the nucleus, while DNA is stored in the cytoplasm of prokaryotes.
Difference between plant and animal cells
Plant cells have a cell wall, as well as a cell membrane. In plants, the cell wall surrounds the cell membrane. This gives the plant cell its unique rectangular shape. Animal cells simply have a cell membrane, but no cell wall.
what is the process of diffusion in biology?
Diffusion is the movement of molecules from an area of high concentration of the molecules to an area with a lower concentration. The difference in the concentrations of the molecules in the two areas is called the concentration gradient
what is the function of a cell membrane?
The cell membrane, also called the plasma membrane, is found in all cells and separates the interior of the cell from the outside environment. The cell membrane consists of a lipid bilayer that is semipermeable. The cell membrane regulates the transport of materials entering and exiting the cell.
what is the difference between active and passive transport in biology?
Active transport requires energy for the movement of molecules whereas passive transport does not require energy for the movement of molecules. In active transport, the molecules move against the concentration gradient whereas in passive transport, the molecules move along the concentration gradient.
describe the structure of a cell membrane
Biological membranes usually involve two layers of phospholipids with their tails pointing inward, an arrangement called a phospholipid bilayer. Cholesterol, another lipid composed of four fused carbon rings, is found alongside phospholipids in the core of the membrane.
what are carrier and channel proteins?
Channel proteins are proteins that create hydrophilic holes in cell membranes, facilitating the transport of molecules down the concentration gradient. Carrier proteins are integral proteins that transport chemicals across the membrane both down and up the concentration gradient.
what occurs in osmosis?
In biology, osmosis is the movement of water molecules from a solution with a high concentration of water molecules to a solution with a lower concentration of water molecules, through a cell’s partially permeable membrane.
what is the difference between the impact of isotonic hypotonic and hypertonic solutions on animal vs plant cells?
If a cell is placed in a hypertonic solution, water will leave the cell, and the cell will shrink. In an isotonic environment, there is no net water movement, so there is no change in the size of the cell. When a cell is placed in a hypotonic environment, water will enter the cell, and the cell will swell.
