Cell Structure and Function, Plasma Membrane and Transport, Energy and Metabolism, Photosynthesis, Cellular Respiration

This collection of flashcards covers key vocabulary and concepts related to cell structure and function, plasma membrane, transport, energy and metabolism, photosynthesis, and cellular respiration.

Cell

The smallest unit that can perform all life processes.

Cell Theory

1. All organisms are made of cells 2. The cell is the basic unit of structure and function 3. All cells come from pre-existing cells.

Eukaryotic cells

Larger cells (10–100 µm) that have a nucleus and membrane-bound organelles.

Prokaryotic cells

Smaller cells (1–10 µm) that lack a nucleus and membrane-bound organelles.

Surface area to volume ratio

Smaller cells have a larger ratio, allowing for more efficient material exchange.

Shapes of bacteria

Coccus (round), Bacillus (rod), Spirillum (spiral).

Cell envelope

Includes the plasma membrane, cell wall, and capsule or slime layer of a bacterial cell.

Appendages in bacteria

Flagella for movement, Fimbriae for attachment, and Pili for DNA transfer.

Conjugation pili

Tube-like structures that allow DNA transfer between bacterial cells.

Nucleoid

The region in a bacterial cell that contains circular DNA.

Peptidoglycan

A structural molecule found in bacterial cell walls that provides rigidity.

Endosymbiont theory

Eukaryotic organelles like mitochondria and chloroplasts evolved from engulfed prokaryotic cells.

Cytoplasm

The jelly-like fluid that holds organelles in a cell.

Ribosomes

Organelles that synthesize proteins.

Mitochondria

Organelles that produce ATP through cellular respiration.

Centrioles

Cell structures that aid in cell division.

Chloroplasts

Organelles that perform photosynthesis in plant cells.

Vacuoles

Storage organelles in cells.

Lysosomes

Organelles that digest waste in cells.

Golgi apparatus

An organelle that processes and packages proteins.

Nucleus

The cell organelle that houses DNA.

Cell wall

A rigid layer that provides structural support to plant cells.

Nucleoplasm

The substance filling the nucleus.

Nuclear envelope

A double-membrane that controls passage in and out of the nucleus.

Chromatin

DNA and protein in the nucleus that condenses to form chromosomes.

Nucleolus

The structure in the nucleus that produces ribosomes.

Endomembrane system

A network of organelles that process and transport materials in the cell.

Chlorophyll

A green pigment that absorbs sunlight for photosynthesis.

Plasma membrane

The barrier that separates the cell from its environment.

Stroma

The fluid inside chloroplasts where the Calvin cycle occurs.

Matrix

The fluid inside mitochondria where the Krebs cycle takes place.

Cytoskeleton

A structural framework made of microfilaments, intermediate filaments, and microtubules.

Plant cell structures

Cell wall, chloroplasts, and central vacuole.

Animal cell structures

Centrioles and lysosomes.

Plasma membrane functions

Separates cell, regulates exchange, communicates, and identifies the cell.

Fluid-mosaic theory

Describes the plasma membrane as flexible with proteins embedded in a bilayer.

Phospholipid

A lipid molecule with a phosphate head and two fatty acid tails.

Glycolipid

A lipid with an attached carbohydrate for cell recognition.

Phospholipid orientation

Hydrophilic heads face outward, hydrophobic tails face inward.

Cholesterol in membranes

Stabilizes membrane fluidity and flexibility.

Protein functions in membranes

Transport, enzymes, recognition, communication, and support.

Fluid

A substance whose molecules move freely.

Passive transport

Movement of molecules that does not require energy.

Active transport

Movement of molecules that requires energy.

Types of passive transport

Diffusion, osmosis, and facilitated diffusion.

Types of active transport

Endocytosis, exocytosis, and pump systems.

Easily diffusing molecules

Small, nonpolar molecules like oxygen and carbon dioxide.

Concentration gradient

The difference in concentration across a space.

Tonicity

The concentration of solute in a solution compared to the cell.

Isotonic solution

Equal concentration of solute; no net movement of water.

Hypotonic solution

Lower concentration of solute; cell gains water.

Hypertonic solution

Higher concentration of solute; cell loses water.

Osmosis

Diffusion of water through a selectively permeable membrane.

Plasmodesmata

Channels between plant cells for communication.

Junction types

Adhesion, tight, gap junctions.

Energy

The ability to do work.

Kinetic energy

Energy of motion.

Potential energy

Stored energy.

First law of thermodynamics

Energy cannot be created or destroyed.

Second law of thermodynamics

Energy conversions increase entropy.

Energy conversion loss

Some energy is lost as heat.

Entropy

A measure of disorder or randomness.

Chemical energy

Energy stored in chemical bonds.

Free energy

Energy available to perform work.

Metabolic pathway

A series of linked reactions that build or break down molecules.

Enzymes

Proteins that speed up reactions by lowering activation energy.

Energy of activation

Energy needed to start a reaction.

Factors affecting reaction speed

Temperature, pH, enzyme or substrate concentration.

Substrates

Reactants that enzymes act upon.

Enzyme-substrate complex

Temporary binding of enzyme and substrate at the active site.

Enzyme inhibition

Molecules that slow enzyme activity; can be competitive or noncompetitive.

Denaturation

Loss of enzyme shape due to heat or pH changes.

Enzyme naming

Usually end with –ase and named after their substrate.

Cofactors and coenzymes

Vitamins and ions that help enzymes function.

Metabolism

All chemical reactions in a cell.

Coupling in metabolism

Using energy from one reaction to drive another.

ATP structure

Adenine, ribose, and three phosphates.

Bond releasing energy

Between 2nd and 3rd phosphate groups of ATP.

Building ATP

ADP + P + energy → ATP.

Redox reactions

Involve electron transfer.

Oxidation

Loss of electrons.

Reduction

Gain of electrons.

Photosynthesis importance

Provides oxygen and glucose, forming the base of the food chain.

Electromagnetic spectrum

All wavelengths of solar radiation.

Short wave radiation

Higher energy wavelengths.

Long wave radiation

Lower energy wavelengths.

Photon

A packet of light energy used in photosynthesis.

Visible light

The portion of light plants use for photosynthesis.

Photosynthesis equation

6CO2 + 6H2O → C6H12O6 + 6O2.

Photosynthesis location

Occurs in chloroplasts of mesophyll cells.

Stoma

Leaf openings that regulate gas exchange.

Granum

A stack of thylakoids.

Thylakoid

Membrane structures in chloroplasts containing chlorophyll.

Light-dependent reactions

Reactions that use light to produce ATP and NADPH.

Pigments

Light-absorbing molecules in plants.

Light-independent reactions

Calvin cycle that uses CO2, ATP, and NADPH to make glucose.

End products of photosynthesis

Glucose and oxygen.

Cellular respiration equation

C6H12O6 + 6O2 → 6CO2 + 6H2O + ATP.

Cellular respiration location

Mitochondria .

Exergonic reaction

A reaction that releases energy.