Ch 2: Structure and Function of Animal Cells

Organelle

Small structures or miniature organs within a cell that have their own function

Nucleus

Spheroid body within a cell, contained in a double membrane, the nuclear envelope, and containing chromosomes and one or more nucleoli. The genetic control center of the Eukaryotic cell.

Chloroplast

An organelle found in plant and algae cells where photosynthesis occurs

Cytoplasm

The contents of a cell surrounding the nucleus. consists of a semifluid medium and organelles.

Vacuole function

Store a variety of things such as water, nutrients, or waste products. Larger in plant cells

Ribosome-

Occurs free in the cytoplasm or attached to the membranes of the endoplasmic reticulum; functions in protein synthesis.

endoplasmic reticulum (ER)-

A complex of membranes within a cell; may bear ribosomes (rough ER) or not (smooth ER).

Rough ER-

has ribosomes and is site of protein synthesis

Smooth ER-

functions in synthesis of lipids and phospholipids and as a detoxification site within cells.

Golgi complex-

A part of the cellular endomembrane system that serves as a collecting and packaging center for secreted polypeptides and proteins.

Lysosomes

cell organelle filled with enzymes needed to break down certain materials in the cell

Centrioles

Cell organelle that aids in cell division in animal cells only

Mitochondria

An eukaryotic cellular organelle in which aerobic metabolism occurs.

Cell membrane (plasma membrane)

phospholipid bilayer that surrounds all cells and regulates what enters and leaves the cell

Phospholipid Bilayer

A double layer of phospholipids that makes up plasma and organelle membranes.

phospholipid structure

hydrophilic head and hydrophobic tail

Receptor protein

Membrane protein that triggers a change in cell activity after binding to a particular substance.

transport protein

protein that moves substances or wastes through the plasma membrane

Diffusion

The movement of particles or molecules from area of high concentration of the particles or molecules to area of lower concentration.

facilitated diffusion

process of diffusion in which molecules pass across the membrane through cell membrane channels

Osmosis

diffusion of water molecules across a membrane.

Active Transport

Mediated transport in which a transmembrane protein transports a molecule across a plasma membrane against a concentration gradient; requires expenditure of energy; contrasts with

Endocytosis

The engulfment of matter by phagocytosis, pinocytosis, receptor-mediated endocytosis, and bulk-phase

Hypertonic solution

A solution in which the concentration of solutes is greater than that of the cell that resides in the solution

hypotonic solution

A solution in which the concentration of solutes is less than that of the cell that resides in the solution

Isotonic solution

A solution in which the concentration of solutes is essentially equal to that of the cell which resides in the solution

Activation Energy

Minimum energy required to start a chemical reaction.

Catalyst (enzyme)

A substance that accelerates a chemical reaction but does not become a part of the end product.

Enzyme

A type of protein that speeds up a chemical reaction in a living thing

Cell size is limited by

surface area to volume ratio

Lysosome

cell organelle filled with enzymes needed to break down certain materials in the cell

Explain why cells need ATP.

Cells need ATP as an immediate source of energy for cellular processes (active transport, making molecules, cell division)

How does the ATP molecule provide a cell with energy?

ATP breaks the bond between its second and third phosphate group releasing energy that can be used to fuel cell process

cellular respiration

Process that releases energy by breaking down glucose and other food molecules in the presence of oxygen

cell respiration equation

C6H12O6 + 6O2 >>>> 6H20 + 6CO2 +ATP

How many ATP are made from one glucose during aerobic cell respiration?

Glycolysis = 2 ATP, Citric Acid Cycle = 2 ATP, ETC = 34 ATP for a total of 38 ATP

Glycolysis

glucose is converted into two 3-carbon units (pyruvic acid) in the cell cytoplasm.

How does fermentation make it possible for glycolysis to occur repeatedly?

Fermentation recycles NADH → NAD+ so it can be used for more fermentation

Number of ATP produced during Glycolysis

2 ATP used, 4 ATP formed

Krebs Cycle (Citric Acid Cycle) location

matrix of mitochondria

Krebs Cycle (Citric Acid Cycle) description

second stage of cellular respiration, in which pyruvic acid is broken down into carbon dioxide in a series of energy-extracting reactions

What role do NADH and FADH₂ play in cellular respiration?

NADH and FADH₂ carry high-energy electrons to the electron transport chain, where their energy is used to produce

Electron Transport Chain (ETC)

A sequence of electron carrier molecules (membrane proteins) that shuttle electrons during the redox reactions that release energy used to make ATP.

oxidative phosphorylation (chemiosmosis) description

Energy carried by electrons from reduced coenzymes, is used to make ATP.

Involves the electron transport chain and chemiosmosis.

ETC and Chemiosmosis location

inner membrane of mitochondria

ETC and Chemiosmosis produces

34 ATP from one Glucose, H2O

Compare aerobic respiration and fermentation in terms of ATP yield and end products

Aerobic respiration: ~36-38 ATP, end products = CO₂ + H₂O. Fermentation: 2 ATP, end products = lactic acid (animals) or ethanol + CO₂ (yeast)

Photosynthesis equation

6CO2 + 6H2O + light energy --> C6H12O6 + 6O2

Why are cell respiration and photosynthesis considered complimentary reactions?

he products of cell respiration are the reactants for photosynthesis. The products of photosynthesis are the reactants for cell respiration