Cell Biology

These flashcards cover the key concepts regarding cell structure and functions, including distinctions between prokaryotic and eukaryotic cells, as well as various organelles.

What are Prokaryotes?

Cells that do not contain a nucleus or membrane-bound organelles, are smaller and simpler than eukaryotes, and contain genetic material.

What distinguishes Eukaryotic cells from Prokaryotic cells?

Eukaryotic cells have a nucleus and membrane-bound organelles, are larger and more complex, and display great variety.

What is the function of the Nucleus?

Contains nearly all the cell's DNA, coding instructions for building proteins, and is surrounded by a nuclear envelope with nuclear pores.

What are Ribosomes responsible for?

They are the site of protein synthesis, receiving coded instructions from the nucleus.

What does the Endoplasmic Reticulum do?

The Endoplasmic Reticulum is an organelle involved in the synthesis and processing of proteins and lipids. It also plays a key role in transporting materials within the cell.

What is the difference between Smooth ER and Rough ER?

Rough ER is studded with ribosomes and processes proteins; Smooth ER does not have ribosomes and processes lipids and carbohydrates.

What is the main function of the Golgi apparatus?

To modify, sort, and package proteins and other materials from the ER for storage or export.

What do Lysosomes do?

They are small organelles filled with enzymes used to digest and break down lipids, carbohydrates, and proteins. Mostly in animals cells.

What is the function of Mitochondria?

They are the 'Powerhouse' of the cell, converting chemical energy in food into usable compounds.

What is the purpose of the Cytoskeleton?

Maintains the 3-D shape of the cell, helps with cell movement, and is made up of long strands of protein.

What are Centrioles and their function?

Paired bundles of microtubules located near the nucleus, helping organize cell division. Only in animal cells.

What is the function of the Cell Membrane?

Regulates what enters and leaves the cell while providing protection and support.

What extra structures do Plant Cells have that Animal Cells do not?

Cell Wall, Central Vacuole, and Chloroplasts.

What is the function of the Cell Wall?

Provides support and protection for plant cells without replacing the cell membrane.

What do Vacuoles do in plant cells?

Can take up to 90% of the plant cell and help support structure by creating pressure; also serve as storage.

What is the function of Chloroplasts?

Capture sunlight and convert it into chemical energy through photosynthesis.

Which organelle is responsible for photosynthesis in plant cells?

Chloroplast.

What does Cytoplasm do?

The cytoplasm is the gel-like substance within the cell membrane that contains organelles and supports the cell's internal structure, allowing for the movement of materials. 

What does the Nucleolus do?

The nucleolus is a structure within the nucleus of a cell that is primarily responsible for producing and assembling ribosome components, essential for protein synthesis.

What does the Nuclear Membrane do?

The nuclear membrane, also known as the nuclear envelope, surrounds the nucleus and controls the flow of substances in and out of the nucleus, protecting the genetic material within.

What do Nuclear Spores?

Nuclear spores are openings in the nuclear membrane that allow for the transport of molecules such as RNA and proteins between the nucleus and the cytoplasm.

What does the Mitochondria create?

Mitochondria create adenosine triphosphate (ATP), which is the primary energy carrier in cells, through the process of cellular respiration.

Eukaryotic examples

include animals, plants, fungi, and protists.

Prokaryotic examples

include bacteria and archaea.

Cilia

are hair-like structures on the surface of some eukaryotic cells that help with the movement of a cell

Flagella 

are long, tail-like structures that aid in the movement of some cells

Cellular Transport

process by which materials enter and leave he cell

Selectively Permeable

some substances can pass across them and others cannot

Passive Transport

is the movement of substances across a cell membrane without the use of energy, typically following a concentration gradient, from high to low

Diffusion

the movement of molecules from an area of high concentration to low concentration, due to random movement of molecules, passive transport

Concentration

the number of molecules in a solution

Osmosis

the diffusion of water across a selectively permeable membrane, moving from an area of high solute concentration to low solute concentration, passive transport

Hypertonic Solution

a high solute concentration outside of the cell causes water to diffuse out of the cell making the cell shrink

Hypotonic Solution

a high solute concentration inside the cell causes water to diffuse into the cell causing the cell to swell and expand.

Isotonic Solution 

the concentration of solute is the same on both sides of the membrane, the water goes in and out of the cell, the cell will stay the same

Facilitated Diffusion 

uses carrier protein to move materials across the cell membrane, no energy is needed, passive transport

Active transport

uses cellular energy to move materials across the cell membrane against the concentration gradient, from low to high

Protein pump

proteins embedded in the cell membrane help move ions and small molecules

Na+/K+ ATPase pump

an enzyme that uses energy (ATP). Moves 3 Na+ ions out of the cell and 2 K+ ions into the cell

Endocytosis

movement of substances into the cell by vacuoles, active transport

Phagocytosis

taking in large particles for food; blood cells consuming bacteria, type of endocytosis

Pinocytosis

taking in water by using vacuoles, type of endocytosis

Exocytosis

movement of substances out of cell by vacuoles

Plasma/ Cell membrane

Thin, flexible boundary between the cell and its watery environment, allows nutrients into the cell, allows waste to level the cell, helps maintain a cell’s homeostasis

Cell membrane structure

made out of a phospholipid bilayer, two layers of phospholipids are arranged tail to tail

Phospholipid bilayer

Phospholipid = glycerol backbone; two fatty acid chains, and a phosphate group,

Why can’t water soluble substances pass through the membrane easily?

Water-soluble substances cannot pass through easily because they are stopped by the middle non-polar section

hydrophilic heads

water-loving heads, has a charge, polar, glycerol and phosphates are here

hydrophobic tails 

water-fearing tails, has no charge, non-polar fatty acid chains that face inward toward each other in the bilayer

Proteins in the cell membrane

Transmit signals inside the cell, act as a support structure, provide pathways through membrane for substances to enter and leave (transport proteins/proteins channels)

Cholesterol in the cell membrane

Non-polar; contributes to fluidity of membrane, prevents fatty acid tails from sticking together 

Carbohydrates in the cell membrane

identifies chemical signals from other cells

Fluid Mosaic model

Components of the plasma membrane are in constant motion sliding past one another

The cell theory

all living things are composed of cells, cells are the basic unit of structure and function in living things, new cells are produced from pre-existing cells

Eye Piece

the lens that you look through

Coarse Focus Adjustment

moves the stage in large increments

Body Tube

the tube that supports the eyepiece

Fine Focus Adjustment

moves the stage in small increments

Revolving Nose piece

the rotating device that holds and changes the lens

High Power Objective

magnification lens with the highest power

Arm

attaches the body tube to the base

Medium Power

Magnifies 10x

Stage

holds the specimen

Stage Clips

clips that keep the slide or specimen from moving on the stage

Diaphragm

controls the amount of light entering the stage

Base 

supports the microscope

Light

allows light on the slide

Low power objective

magnification lens with lowest power