2nd Exam Flashcards

Robert Hook

Used a compound microscope and examined thin cork slices that contained box-like structures he called cells.

Anton Van Leeuwenhoek

Dutchman, created many early microscopes, father of microbiology

Robert Brown

Noted that all plants contain small dense round body called a nucleus

Matthias Schledien 

Theorized that all plants were made of cells 

Theodor Schwann

Proposed that all animals were made of cells 

Rudoplh Virchow

Stated that all new cells arise from preexisting cells

Cell theory

Cells are the basic unit of organization and function in all living organisms

All cells come from other cells

All living cells have evolved from a common ancestor 

What helps cells maintain homeostasis?

Cell organization and size are critical in maintaining homeostasis

They have many organelles, internal structures that carry our specific functions

Plasma Membrane

Surrounds the cell, separates cell from external environment, maintains internal conditions, allows the cell to exchange materials with outer world

Sectioning

The thin slicing of materials

Staining

Process by which you add color to materials on slides to better enhance vision

Cell Fractionation

Purifies organelles, helps study cell structure

Proteins

Synthesized on ribosomes, processed in endoplasmic reticulum, processed by the Golgi complex, transported by vesicles 

Prokaryotic Cells

No internal membrane organization, cell wall, ribosomes, flagella

Eukaryotic cells

Membrane encloses nucleus, cytoplasm contains organelles, cytosol fluid components

Plant cells

Rigid cell walls, plastids, large vacuoles that store water, no centrioles

Cell membrane

Divides cells into compartments, vesicles transport material between compartments, important in energy storage and conversion

Endocytosis

Takes in food by forming new vesicle from plasma membrane

Exocytosis

Removes food by fusion of vesicles

Nucleus

Control center of cell , genetic info coded in DNA

Nuclear pores

Communicate with cytoplasm

Nuclear envelope

Double membrane that encloses the nucleus in eukaryotic cells

Chromatin 

Looks like noodles before genetic information is in putted by genes

Chromosomes

DNA condensed for cell division

Nucleolus

Ribosomal RNA synthesis

Ribosome assembly 

Endoplasmic Reticulum 

Network of folded membranes in cytosol 

Smooth ER

Lipid synthesis, calcium ion storage- nerve function, detoxifying enzymes

Rough ER

Ribosomes on outer surface, assembles proteins

Golgi Complex

Process proteins synthesized by ER, manufactures lysosomes (breaks down)

Consists of cisternae (stacks of flattened membranous sacs)

Transport Vesicles 

Formed by membrane budding, move glycoproteins 

From ER to Golgi complex, carry modified proteins to specific destination 

Lysosomes

Breaks down structures

Vacuoles

Store materials in plant cells

Peroxisomes

Produce and degrade hydrogen peroxide, product of aerobic cellular respiration

Mitochondria

Site of aerobic respiration, double membrane (inner membrane folded (cristae)), important in apoptosis (programmed cell death-webbed feet to hands)

Aerobic Respiration 

Breaks down nutrients using oxygen

Plastids

Organelles that produce and store food, in cells of plant and algae 

Chloroplast

Plastids that carry out photosynthesis

Stroma

Fluid-filled space enclosed by inner membrane of chloroplast

Grana

Stacks of membranous sacs, suspended in stroma

Chlorophyll 

Green pigment in thylakoid membrane, traps light energy and tuns it into chemical energy in ATP

Cytoskeleton

Microtubles, hollow tublin cylinders

Centrosome

Usually contains 2 centrioles, each centriole has 9×3 arrangement of micro tubules

Cilia and flagella

Thin, marble structure, project from cell surface, function in movement

Cell Wall

Cellulose and other polysaccharides, for rigid cell wall, in plant cells, fungi, bacteria 

Diffusion

Net movement of substance down its concentration gradient from higher to lower concentration

Osmosis

Diffusion of water from higher to lower concentration

Isotonic solution

Equal solute solution

Hypertonic solution

Cell loses water to surroundings

Hypotonic solution 

Water enters, cell swells 

Eukaryotic cells

DNA in nucleus, cytoplasm contains organelles

Prokaryotic cell

Has a nucleoid, cell wall, ribosomes, flagella, no internal membrane organization

Surface to volume ratio

Ratio of plasma membrane to cell’s volume, important in determining cell size

The bigger the cell, small SVR, the smaller the cell, big SVR

In what temperature will molecule move faster?

A warmer room will cause the molecules to move faster.

Animal cells

No cell wall, lysosomes, centrioles, and many vacuoles.

Active transport

Requires energy (ATP) to move solute

Selective permeability

Allowing substances to cross more easily than others

Transport molecules

Span the membrane, helps hydrophilic substances move through membranes

Passive transport

Diffusion of a substance across a membrane w/o any energy

Amphipathic 

Both hydrophilic and hydrophobic regions, EX: phospholipids

What is the cell membrane made out of?

Proteins and lipids

TEM

Transmission electron microscope, uses electrons instead of light, allows to see internal structures of sample in 2D

SEM

Scanning Electron microscope, uses electrons instead of light, allows to see the surface of a sample in 3D

Compound light microscope

Shines light through a sample, light passed through objective lens creating real, enlarged image, the image travels to ocular lens to further magnify it

Stereomicroscope 

Also known a dissecting microscope, used to view large specimens, dissecting organism/microsurgery, provides 3D image