Lecture 3: Cell biology

Flashcards for Cell Biology Lecture

Robert Hooke

Mid 1600s - first observed + described cells in cork

Antony van Leeuwenhoek

Late 1600s - observed blood cells, sperm, + microorganisms - First to observe living cells

Robert Brown

1820s - observed + discovered nuclei in plant cells - English botanist + naturalist

Cell Theory

All living organisms made up of one or more cells; all cells come from preexisting cells

Prokaryotes

Bacterial cells; in two domains (Domain Bacteria, Domain Archaebacteria); Doesn’t have nucleus; DNA loose in cell

Eukaryotic cells

“Has a nucleus”, 5 components = Nucleus, Organelles, Cytosol, Cytoskeleton, and plasma membrane. Generally larger; Often multicellular; Many different organelles

Prokaryotic

"Before nucleus” - DNA not in nucleus

Prokaryotic Cells

Generally smaller; Always single-celled; Lack of organelles

Nucleus

Contains DNA - DNA has info for protein production - Surrounded by double membrane - “Nuclear envelope” formed by two layers of phospholipids

Ribosomes

Packets of proteins used by cell to make more protein

Rough Endoplasmic Reticulum (RER)

Folded up continuation of nuclear envelope - 1st component of endomembrane system - Aids w/ protein processing - Appears rough b/c of ribosomes studding surface. (Found in cytoplasm)

Smooth Endoplasmic Reticulum

Produces fats in cell - Detoxification of harmful substances. Ex. Alcohol detoxified largely in SER of liver cells.

Vesicles

Packages in cell that transport materials to other parts of cell. Newly made proteins(enzyme) or fat (hormone) enclosed in vesicle.

Golgi Complex

A component of endomembrane system - Completes molecules like proteins made by the ribosomes or fats made by the SER - series of connected membrane sacs ( found in cytoplasm)

Cis Face

Substances enter the Golgi on the receiving face toward the inside of the cell nucleus.

Lysosomes

Present in hundreds of copies in the cell - Membrane-bound sacs w/ acidic interior containing various hydrolytic enzymes - Digests worn-out cellular materials - ONLY IN ANIMAL CELLS (Found in cytoplasm)

Mitochondria

The powerhouse of a cell - Oxidizes (burn) food to release energy.(oxygen is required for this process), (Found in cytoplasm)

Cytoskeleton

Literally, the cell’s skeleton - Network of protein filaments inside a cell. Has 3 fibers: microfilaments, intermediate filaments, microtubules. Functions = cell structure, movement and movement of materials within cells. (Found in cytoplasm)

Microfilaments

Have a major structural role and allow movement of cell

Microtubules

Components cilia and flagella - Hairlike extensions of cell; movement moves the structures. Ex. Sperm(sticky) has a tail called a flagella

Cell Wall

Protective covering external to membrane - Present in virtually all plants - Contain cellulose - Limits water uptake - only in plant cells (Outside plasma membrane)

Central Vacuole

May comprise 90% of cell volume - Mostly filled w/ water - Stores nutrients - Degrades waste products - Balances cell pH - only in plants (Found in cytoplasm)

Chloroplasts

Are the site of photosynthesis - Formed by layers of membrane which have the pigment chlorophyll embedded in the membrane layers - only in plants (Found in Cytoplasm)

Chromoplasts

No chlorophyll; Color of fruits and flowers red to yellow

Amyloplasts

No pigments - Store starch

Unicellular

Organisms consisting of a single cell, capable of performing all life processes. Ex. Giardia, year cells, bacteria (asexual reproduction)

Multicellular

Organisms consisting of multiple cells, which often specialize in different functions, enabling complex structures and systems. Ex. Blood (humans) or plants

Plasma membrane

All cells have a PM. These are made of 2 layers of fat called phospholipids.

Eukaryotic Cells (Animal)

Plasma membrane, Nucleus, Ribosomes, Endoplasmic reticulum, Golgi body, Vesicles, Mitochondria.

Cell membrane

The outermost boundary of a cell that regulates the passage of substances in and out, providing structure and protection.

Endocytosis

Taking into the cell. (Think of swallowing food)

Exocytosis

The process of expelling materials from a cell through vesicles that fuse with the cell membrane, thereby releasing their contents outside. (found in cytoplasm)

Cilia

Present in large #’s on ciliated cells, beat in unison, beating moves the cell + moves material across the wall.

Size of cells

The cells requirement for materials increase, but the ability to ship these materials does not increase enough hence cells must be small to properly function.

Cytosol

Found in cytoplasm. The protein rich fluid immerses organelles and the cytoskeleton.