Bio Midterm

Photosynthesis

Photosynthesis

Process used by autotrophs to capture light energy and convert carbon dioxide and water into oxygen and energy-rich carbohydrates.

Light-dependent Reactions

Occur in the thylakoid membrane of chloroplasts, require light energy and water, produce ATP, NADPH, and oxygen as byproducts.

Electron Transport Chain

Series of reactions that occur in the thylakoid membrane, where electrons are passed along and ATP and NADPH are produced.

Calvin Cycle

Occurs in the stroma of chloroplasts, uses ATP, NADPH, and carbon dioxide to produce glucose and regenerate starting molecules.

Cell

Basic unit of life.

Organelles

Specialized structures within a cell.

Prokaryotic Cells

Lack a nucleus, simple structure, examples include bacteria and archaea.

Eukaryotic Cells

Have a nucleus, complex structure, examples include animals, plants, and fungi.

Reproduce

Ability to produce offspring, can be sexual or asexual.

DNA

Biological inheritance carried in DNA.

Cell Wall

Provides shape and protection, composed of bacteria, porous.

Cell Membrane

Controls entry and exit of substances, phospholipid bilayer with embedded proteins.

Cytoplasm

Gel-like substance inside the cell, contains enzymes and cellular structures.

Nucleoid

Region where DNA is located, not enclosed by a membrane.

Ribosomes

Site of protein synthesis, composed of RNA and proteins, located on rough ER or in cytoplasm.

Nucleus

Contains DNA, controls cell activities.

Mitochondria

Produces energy (ATP) through cellular respiration, double membrane structure.

Chloroplasts

Found in plant cells, site of photosynthesis, contains chlorophyll.

Lysosomes

Contains digestive enzymes, breaks down waste materials.

Vacuoles

Stores water, nutrients, and waste, large central vacuole in plant cells.

Cellular Respiration

Process of energy conversion that releases energy from food in the presence of oxygen.

Glycolysis

Sugar breaking, glucose is broken into 2 molecules of pyruvic acid, produces ATP and NADH.

Krebs Cycle (Citric Acid Cycle)

Pyruvic acid is broken down into carbon dioxide, produces ATP, NADH, and FADH2.

Electron Transport Chain

Uses electrons to synthesize ATP from ADP, produces water as a byproduct.

Fermentation

Anaerobic process that occurs when oxygen is not present, produces lactic acid or alcohol and carbon dioxide.

Ionic Bond

Chemical bond formed when one or more electrons are transferred from one atom to another.

Covalent Bond

Type of bond between atoms in which the electrons are shared.

Hydrogen Bond

Attraction between a hydrogen atom with a partial positive charge and one with a partial negative charge.

Cohesion

Attraction between molecules of the same substance.

Adhesion

Attraction between molecules of different substances.

Heat Capacity

Amount of energy needed to raise the temperature of a substance.

Solution

Mixture in which all components are equally distributed.

Acid

Compound that releases H+ ions into solutions.

Base

Compound that produces OH- ions into a solution.

Enzyme

Biological catalysts that speed up chemical reactions.

Activation Energy

Amount of energy required to start a chemical reaction.

Catalyst

Substance that speeds up a reaction.

Monomer

Small compound that can join together with other compounds to form polymers.

Polymer

Larger compound made up of monomers.

Dehydration Synthesis

Creation of larger molecules from smaller molecules during the release of water.

Hydrolysis

Use of water to break chemical bonds.

Carbohydrate

Made up of carbon, hydrogen, and oxygen, provides fast source of energy and cell support.

Lipid

Made up of carbon, hydrogen, and oxygen, stores long-term energy and forms parts of membranes.

Nucleotide

Monomer that makes up nucleic acids.

Nucleic Acid

Made up of carbon, hydrogen, oxygen, nitrogen, and phosphorus, transfers chemical energy and contains genetic information.

Protein

Made up of carbon, hydrogen, oxygen, and nitrogen, responsible for cell communication and structure.

Amino Acid

Building blocks of proteins.

pH Scale

Measurement system based on the concentration of H+ ions in a solution.

Acidic

Solutions with a pH below 7, have more H+ ions.

Basic

Solutions with a pH above 7, have more OH

Rough ER

The site where proteins are synthesized and modified before being sent for packaging and sorting.

Vacuole

A large fluid-filled sac in the cell that stores nutrients, water, and salt.

Lysosome

An organelle filled with enzymes that break down lipids, carbs, and proteins into smaller molecules for the cell to use.

Cytoskeleton

A network of protein filaments that helps maintain the cell's shape and is involved in molecular movement.

Chloroplast

An organelle that captures energy from the sun and converts it into chemical energy through photosynthesis.

Mitochondrion

Known as the "powerhouse" of the cell, it converts energy from food into a more convenient form for the cell to use.

Cell wall

Provides structure and support to the cell, especially against osmotic stress.

Lipid bilayer

A flexible double-layered sheet that makes up the cell membrane, separating the cell from its surroundings.

Selective permeability

The property of biological membranes to allow some molecules to pass through while excluding others.

Diffusion

The movement of particles from an area of higher concentration to an area of lower concentration through the cell membrane.

Facilitated diffusion

The movement of particles across the cell membrane through channels.

Aquaporin

A channel protein that facilitates the passage of water across the cell membrane.

Osmosis

The diffusion of water through a selectively permeable membrane.

Isotonic

When the concentration of two solutions is the same.

Hypotonic

When comparing two solutions, the one with a higher concentration.

Hypertonic

When comparing two solutions, the one with a lower concentration.

Osmotic Pressure

The pressure that must be applied to the solution side to stop fluid movement.

Cellular signals

The process by which cells respond to internal signals.

Receptor

A specific protein that binds to molecular messengers (hormones) due to its complementary shape.

ATP

Adenosine triphosphate, a compound used by cells to store and release energy, often referred to as the "currency" for energy.

Photosynthesis

The process by which light energy is converted into chemical energy, performed by plants.

Pigment

Light-absorbing molecules used by plants to capture the sun's energy.

Chlorophyll

The principal pigment in plants responsible for capturing light energy during photosynthesis.

Thylakoid

Saclike photosynthetic membranes found in chloroplasts.

Stroma

The fluid portion of the chloroplast, surrounding the thylakoid membranes.

Electron carrier

A molecule capable of accepting one or more electrons from an electron donor.

NADP+

A carrier molecule that transfers high-energy electrons from chlorophyll to other molecules.

Light-dependent reactions

Reactions that use energy from light to produce ATP and NADP+.

Light-independent reactions

Reactions that do not require light energy and use ATP and NADPH to build high-energy compounds.

Photosystems

Clusters of chlorophyll and proteins found in the thylakoid membranes.

ETC (Electron Transport Chain)

Electron carrier proteins that shuttle high-energy electrons during ATP-generating reactions.

ATP synthase

A cluster of proteins that span the thylakoid membrane, allowing hydrogen ions to pass through and generate ATP.

Calvin Cycle

The light-independent reactions of photosynthesis in which ATP and NADPH are used to build high-energy compounds like sugar.

Calorie

The amount of energy needed to raise the temperature of one gram of water by one degree Celsius.

Cellular Respiration

The process by which cells release energy by breaking down glucose in the presence of oxygen.

Aerobic

A process that requires oxygen.

Anaerobic

A process that does not require oxygen.

Glycolysis

The first stage of cellular respiration, where one glucose molecule is broken down into two pyruvic acid molecules.

NAD+

An electron carrier involved in glycolysis.

Krebs cycle

The second stage of cellular respiration, where the two pyruvates are broken down into CO2, producing NADH, FADH2, and ATP.

ETC (Cellular Respiration)

Occurs in the cristae of the mitochondria and produces the majority of ATP in cellular respiration (36 ATP).

Fermentation

The process by which cells release energy in the absence of oxygen.

Alcoholic fermentation

The result of fermentation in yeast cells.

Lactic acid fermentation

The result of fermentation in muscle cells.