Chapter 4-6 Overview

What are the three basic principles of the cell theory?

1. All organisms are composed of cells. 2. Cells are the basic units of structure and function in organisms. 3. Cells come only from pre-existing cells.

All cells have __________, cytoplasm, chromosomes, and ribosomes.

the cell membrane (plasma membrane)

Define Prokaryotic cells.

Single-celled organisms without a nucleus or other membrane-bound organelles; examples include bacteria and archaea.

What is the defining feature of Eukaryotic cells?

A well-defined nucleus surrounded by a membrane.

Name two types of cells found in every organism.

Prokaryotes and Eukaryotes.

Fill in the Blank: Ribosomes are sites of __________ synthesis.

protein

What is the main function of the Endoplasmic Reticulum (ER)?

Provides mechanical support and transportation, and compartmentalizes the cell.

What is the role of the Golgi Complex?

Modifies, processes, and sorts proteins for distribution.

What are Mitochondria known as?

Power stations that convert energy from organic molecules into ATP.

Fill in the Blank: Lysosomes contain __________ that break down old organelles and debris.

digestive enzymes

What do Vacuoles store?

Water, food, wastes, salts, or pigments.

Define the term 'Peroxisomes'.

Organelles that detoxify substances, producing hydrogen peroxide as a byproduct.

What are microtubules made of?

The protein tubulin.

Fill in the Blank: Microfilaments are made of the protein __________.

actin

What are Cilia and Flagella used for?

Locomotion in single-celled organisms.

What is the structure of a cell membrane?

Made of a lipid bi-layer with embedded proteins.

What is the fluid-mosaic model?

Describes the arrangement of lipids and proteins in the cell membrane as not being in fixed positions.

What type of proteins pass through the membrane?

Integral proteins.

Fill in the Blank: Some materials can pass in and out of the cell due to __________ permeability.

selective

Define Passive Transport.

Natural movement of molecules to balance concentrations without requiring energy.

What occurs in a hypertonic solution?

The solution has more total dissolved solutes than the cell, causing the cell to shrink.

What is the sodium-potassium pump an example of?

Active transport.

What are the three steps of cell communication?

Reception, Transduction, and Response.

What does metabolism encompass?

All of the cell's chemical reactions.

Fill in the Blank: __________ reactions have products with less energy than the reactants.

Exergonic

What are Enzymes?

Biological catalysts that speed up reactions by lowering the activation energy.

Define 'denatured' in relation to enzymes.

When an enzyme's structure is altered by unfavorable environmental conditions.

What effect does temperature have on enzyme activity?

Increasing temperature can increase reaction rates, but too much heat can denature enzymes.

Fill in the Blank: At an incorrect pH, __________ bonds in enzymes can be disrupted.

hydrogen

What happens when the substrate concentration reaches the saturation point?

The reaction can no longer speed up as all enzymes are bound by substrate.

What does the term 'ATP' stand for?

Adenosine Triphosphate.

What type of reaction requires an energy input?

Endergonic reactions.

Fill in the Blank: Competitive inhibitors fit into the __________ site of an enzyme.

active

What are the parts of Eukaryotic cells?

Nucleus, Ribosomes, Endoplasmic Reticulum, Golgi Complex, Mitochondria, Lysosomes, Vacuoles, Peroxisomes, Cytoskeleton.

What is the primary function of Ribosomes?

Manufacture all the proteins the cell requires.

Fill in the Blank: The __________ is responsible for the cell’s ability to reproduce and directs cellular activities.

nucleus

What does the cytoskeleton do?

Determines the shape of a cell with a network of protein fibers.

What are lysosomes involved in during apoptosis?

Programmed cell death.

Fill in the Blank: The __________ easily pass through the cell membrane due to their small size.

small hydrophobic molecules

What does the Smooth ER produce?

Lipids, hormones, and steroids.

What type of diffusion requires a channel-type protein?

Facilitated diffusion.

Fill in the Blank: Cells recognize other cells through __________ proteins.

membrane function

What is the role of cholesterol in the cell membrane?

Helps keep the membrane fluid.

What happens in an isotonic environment?

The solute concentration is the same inside and outside of the cell.

Fill in the Blank: The interior folds of mitochondria are known as __________.

cristae.

What is produced as a byproduct of detoxifying substances in Peroxisomes?

Hydrogen peroxide (H2O2).

Define 'facilitated diffusion'.

Diffusion that requires the help of a channel-type protein.

What defines primary active transport?

Direct utilization of ATP to transport substances.

Fill in the Blank: __________ refers to cellular communication via chemical signals.

Cell signaling