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Ch. 7 Test Bio Test

Terms in this set (73)

cell
basic unit of all forms of life
cell theory
a fundamental concept of biology
What does the cell theory state?
All living things are made up of cells, cells are the basic unit of structure and function in living things, new cells are produced from existing cells
cell membrane
a thin, flexible barrier that all cells are surrounded by, sometimes called the plasma membrane
nucleus
a large membrane-enclosed structure that contains genetic material in the forms of DNA and controls many of the cells activities
Eukaryotes
cells that enclose their DNA in nuclei
Prokaryotes
cells that don't enclose DNA in nuclei
How are prokaryotic and eukaryotic cells different?
Prokaryotic cells do not separate their genetic material within the nucleus. In Eukaryotic cells , the nucleus separates the genetic material from the rest of the cell
What are membranes made out of?
phospholipids
What are phospholipids made out of?
A phosphate head and two fatty acid tails
The phosphate head is______________
polar; hydrophilic- water loving
The two fatty acid tails are______________________
non polar; hydrophobic- water fearing
What is the structure of the membrane?
phospholipid bilayer
What are embedded in the phospholipid bilayer and what do they do?
proteins, they help different substances get in and out of the cell
Passive Transport does not require...
cell energy
Diffusion
particles move from an area of higher concentration to an area of lower concentration (passive transport)
Facilitated Diffusion
assisted by protein channels in the membrane- each protein is specific to the substance it lets through (passive transport)
Osmosis
diffusion of water across a selectively permeable membrane
Water follows the...
solute
Isotonic
the concentration of the solute is the same inside the cell as it is outside the cell, H2O will enter and exit the cell at the same rate
Hypotonic
a solution has a lower solute concentration than the cell, net movement of water is into the cell
Random movement
how any molecule gets somewhere when water moves, it moves until it bumps into something
Net movement
total of all that is going in and out
Hypertonic
the concentration of the solute that is outside the cell is higher than the solute of what's inside the cell, the net movement is out of the cell
Active transport requires
cell energy
Molecular Transport
ions and other molecules pumped across the membrane by proteins
Bulk Transport
large molecules and particles
Endocytosis
into the cell
Phagocytosis
"cell eating"
Pinocytosis
"cell drinking"
Exocytosis
out of the cell
Homeostasis
stable internal environment
Tissue
group of similar cells that perform a particular function
Organ
group of tissues that work together to perform closely related functions
Organ system
group of organs that work together to perform a specific function
Receptor
on or in a cell, a specific protein whose shape fits that of a specific molecular messenger, such as a hormone
Robert Hooke
used a compound microscope to see chambers within cork and named the "cells"
Anton van Leeuwenhoek
used a single-lens microscope to observe pond water and other things and found bacteria, invented the microscope
How do microscopes work?
most microscopes use lenses to magnify the image of an object by focusing light or electrons
2 types of electron microscopes
transmission and scanning
How did the invention of the microscope help the development of the cell theory?
The microscope enabled people to see cells and study the parts of cells. This ability enabled scientists to learn that all organisms are composed of cells
What is the role of the cell nucleus?
the nucleus contains DNA and, with it, the coded instructions for making proteins and other important molecules, controls many of the cells activities
What are the functions of vacuoles, lysosomes, and the cytoskeleton?
vacuoles- store materials like water, salts, proteins, and carbohydrates
lysosomes- break down large molecules into smaller ones that can be used by the cell
cytoskeleton- helps the cell maintain its shape and is also involved in movement
What are the functions of chloroplasts and mitochondria?
chloroplasts- captures sunlight and converts it into food
mitochondria- releases energy from food
What is the function of the cell membrane?
regulates entry and exit of substances and protects and supports the cell
cytoplasm
portion of cell outside the nucleus
lysosome
small organelles filled with enzymes
cytoskeleton
network of protein filaments, contains microtubules and microfilaments
centriole
located near the nucleus and help organize cell division
ribosome
small particles of RNA and protein found throughout the cytoplasm in all cells
endoplasmic reticulum
an internal membrane system
Golgi apparatus
stack of flattened membranes
cell wall
a strong supporting layer around the membrane
lipid bilayer
gives cell membranes a flexible structure that forms a strong barrier between the cell and its surroundings
selectively permeable
only some substances can pass across them and others cannot
What are the two major parts of the cell?
cytoplasm with organelles, nucleus
What is the difference between a rough and smooth ER?
rough ER has surface ribosomes while the smooth ER does not
labeled animal cell diagram (only label ones talked about in class)
labeled plant cell diagram (only label ones talked about in class)
cellular control center
nucleus: contains DNA
organelles that store, clean up, and support
vacuoles and vesicles: store materials
lysosomes: break down and recycle macromolecules
cytoskeleton: maintains cell shape; moves cell parts; helps cells move
centrioles: organize cell division
organelles that build proteins
ribosomes: makes proteins
endoplasmic reticulum: location for protein and lipid assembly
Golgi apparatus: processes and packages proteins and other materials
cellular boundaries
cell wall: shapes, supports, and protects the cell
cell membrane: regulates materials entering and leaving cell ; protects and supports cell
what is passive transport?
passive transport (including diffusion and osmosis) is the movement of materials across the cell membrane without cellular energy
what is active transport?
the movement of materials against a concentration difference, active transport requires energy
aquaporin
water channel proteins
osmotic pressure
the net movement of water out of or into a cell produces a force known as osmotic pressure
what is the difference between diffusion and facilitated diffusion?
diffusion occurs when molecules spread out by moving randomly. Facilitated diffusion is when protein channels help molecules move across the cell membrane
how do individual cells maintain homeostasis?
to maintain homeostasis, unicellular organisms grow, respond to the environment, transform energy, and reproduce
how do the cells of multicellular organisms work together to maintain homeostasis?
the cells of multicellular organisms become specialized for particular tasks and communicate with one another to maintain homeostasis
microtubules
form centrioles and move chromosomes during cell division, transport and support
microfilaments
produce a tough, flexible framework that supports the cell and help the cell move
nucleolus
makes ribosomes
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