Biology A - Cell Biology Study Set

second rule of cell theory

cells are the basic units of structure and function in living things

nucleus

-contains DNA

-coded instructions for producing protein and other molecules

-nuclear envelope, chromatin, nucleolus

nuclear envelope

layer of two membranes with pores that surround the nucleus

chromatin

a complex of DNA bound to proteins that make up chromosomes

chromosomes

thread-like structures that carry the cells genetic information in the nucleus within a chromatin

nucleolus

small dense region in the nucleus that begins the assembly of ribosomes (RNA + protein)

ribosomes

assembled proteins which have small particles of RNA + protein

first rule of cell theory

all living things are made up of cells

third rule of cell theory

new cells can only be produced from existing cells

facts of light microscopes

-a beam of light passing through a specimen

-only produce clear images up to 1000x

-living things

-stains or dyes

general facts of electron microscopes

-only produce clear images up to 1 billionth of a meter

-non-living things or dead tissue

-electrons scatter in air, therefore, vacuum sealed

-artificial coloring on computer

transmission electron microscope

-a beam of electrons through a thin sample

-thin slice of specimen

scanning electron microscope

-a beam of electrons scanned on surface

-no need to cut specimen

micrograph

photo of sample through microscope

cells size

5-50 micrometers

cell membrane / plasma membrane

a thin, flexible barrier made of a lipid bi-layer

lipid bi-layer

has an outside layer that is hydrophilic, and an inside layer that is hydrophobic

plasma

fluid portion of the blood

prokaryotic cells

-no nucleus

-cytoplasm holds DNA

-always unicellular

eukaryotic cells

-nucleus

-includes many uni-cellular organisms, but mostly multicellular

-includes many animal cells

-endoplasmic reticulum

rough endoplasmic reticulum

synthesizes proteins on ribosomes, cellular proteins on the free ribosomes, and export them to the golgi apparatus

smooth endoplasmic reticulum

a collection of enzymes that complete specific tasks like the detoxification of drugs, synthesizing lipids, and playing an important role in the synthesis of carbohydrates

golgi apparatus

modifies-sorts-packages proteins and other materials from the er for storage or release from the cell

vacuoles

stores materials like water, salt, proteins, and carbohydrates

central vacuole

only in plant cells, it contains liquid so the pressure allows the plant to hold up leaves and flowers

lysosomes

small organelles filled with enzymes that break down lipids, carbohydrates, and proteins into small molecules to be used by the cell, and also breaks down old or no longer useful organelles

cytoskeleton

a network of protein filaments that give eukaryotic cells their shape and internal organization while maintaining cell shape and helps to transport materials between parts of the cell

microfilaments

thread-like structures made of protein and actin that forms extensive networks to help support cell shape and allows the cell to sometimes move with help of the cytoskeleton

centrials

helps organize cell division, near the nucleus

chloroplasts

only in plants and other organisms, basically solar power plants, they have 2 membranes with large stacks of other membranes that have chlorophyll inside

mitochondria

2 membranes with the inner membrane folded inside, mostly in all eukaryotes, some plants, and converts chemical energy stored in food molecules

cell wall

an outside cell membrane that supports, shapes, and protects. present in most prokaryotes and eukaryotes, plants and fungi, NOT in animal cells

permeable (to)

a substance is able to cross the membrane

impermeable (to)

a substance cannot pass through the membrane

selectively permeable / semipermeable membrane

some substances can pass, some can't

organelles that are like the cellular control center

nucleus

organelles that build proteins

ribosomes, endoplasmic reticulum, golgi apparatus

organelles that store, clean-up, and support

vacuoles and vesicles, lysosomes, cytoskeleton, centrioles

organelles that capture and release energy

chloroplasts and mitochondria

cellular boundaries

cell wall and cell membrane

homeostasis

the tendency to remain in a state of relatively stable equilibrium between independent elements

cytoplasm

the portion of the cell outside the nucleus; holds the DNA in prokaryotic cells

organelles

compounds of a cells structure that perform specialized tasks

diffusion

the process by which particles move from an area of high concentration to an area of low concentration

equilibrium

the state in which the concentration on both sides of a cell membrane are the same

passive transport

the movement of molecules across the cell membrane without using cellular energy

facilitated diffusion

when molecules that could not pass and diffuse across the membrane go through special protein channels where there are hundreds of different proteins that allow various substances and molecules to cross the cell membranes

aquaporins

the inside of the lipid bi-layer is hydrophobic, so water goes through facilitated diffusion to get inside the cell

osmosis

the diffusion of water through a selectively permeable membrane

isotonic

when the difference between the ratio of solutes vs water is the same in two solutions, "same strength" - strength referring to solutes not water

hypertonic

when there is a higher concentration between the ratio of solutes vs water than another solution, "above strength" - strength referring to solutes not water

hypotonic

when there is a lower concentration between the ratio of solutes vs water than another solution, "below strength" - strength referring to solutes not water

osmotic pressure

the force on a cell produced by the net movement of water in or out of a cell which is driven by the difference in solute concentrations

osmotic pressure effects

can cause a cell in a hypertonic solution to shrink, and a cell in hypotonic solution to swell

why are cells hypertonic to fresh water?

most cells contain many dissolved molecules, they are mostly always hypertonic to water

why do plant cells not change shape externally when inflicted by osmotic pressure

the central vacuole shrinks or swells, but the cell wall does not allow for external changes in shape, but can endure injuries

active transport

the movement of materials against a concentration difference and it requires energy since it works against diffusion

endocytosis

the process of larger clumps of material that goes into the cell by means of infoldings, or pockets, of the cell membrane where when it goes through, it forms a vesicle or vacuole

phagocytosis

a form of endocytosis where extensions of the cytoplasm surround a particle and packages it in a food vacuole where the cell then engulfs it

who uses phagocytosis?

white blood cells use phagocytosis to remove damaged or foreign cells to destroy them and amoebas use it for food

exocytosis

the process of releasing large amounts of material where the membrane of the vesicle or vacuole surrounding the material fuses with the cell membrane which force the content out of the cell

how are specialized cells organized?

specialised cells are organized into tissues, organs, and organ systems

what is a tissue?

a group of similar cells that perform a certain function

what is an organ?

a group of tissues working together to complete a series of tasks

organ system

a group of organs working together to perform a certain function

how do cells in large organisms communicate?

chemical signals that are pass from one cell to another that can speed up or slow down what a cell is doing or change its task dramatically

what is a receptor?

a protein that detects a signal molecule and performs an action in response

energy

The ability to do work or cause change

ATP (adenosine triphosphate)

one of the most important energy-storing compounds that consists of the 5-carbon sugar ribose, adenosine, and three phosphate groups

ADP (adenosine diphosphate)

adenosine and 5-carbon sugar ribose with two phosphate groups that can accept another phosphate group and become ATP

what can ATP do?

can release and store energy by breaking and reforming the bonds between its phosphate groups. it is exceptionally useful as basic energy source for cells

is ATP a good long term energy source?

no, cells only have enough ATP to last a few seconds of intense activity

heterotroph

organisms that obtain food by consuming other living things

autotroph

organisms that make their own food

photosynthesis

the utilization of the energy in sunlight in order to convert water and carbon dioxide ( low-energy reactants ) to sugars and oxygen ( high-energy products)

how does the sun provide energy?

energy from the sun travels to the earth in the form of light, which is different wavelengths and make up what is known as the visible spectrum where we can see different wavelengths as different colors

how do photosynthetic organisms capture energy?

photosynthetic organisms use pigments, or light-absorbing compounds, to capture the energy in sunlight

how does chlorophyll work?

they absorb the blue-violet and red regions of the visible spectrum well, but they reflect the green region, giving them a green appearance

what does the chloroplast do?

is where photosynthesis takes place, found in plants and other photosynthetic eukaryotes

chloroplast

two envelope membranes that are filled with sac-like chlorophyll, which contain membrances called thylakoids

thylakoids

interconnected membranous sacs arranged in stacks called grana and are suspended in the stroma

stroma

the portion of the chloroplasts outside of the thylakoids where there is fluid

besides chlorophyll, what other pigments are found in the chloroplasts?

plants also contain red and orange pigments, like carotene, that absorbs light in other spectrums, but are invisible to the eye because the chlorophyll color is overwhelming

why do leaves turn colors in the fall?

when the temperature drops with seasons, chlorophyll is one of the first pigments to break down, leaving the other pigments to show up

why is chlorophyll so important?

it absorbs light very efficiently with transferring light energy to its own high energy electrons which can do chemical work

how are the high energy electrons from chlorophyll transported?

via an electron carrier

electron carriers

a compound that can accept a pair of high-energy electrons and transfer them, along with most of their energy, to another molecule

NADP+ (nicotinamide adenine dinucleotide phosphate)

an electron carrier that accepts and holds 2 high-energy electrons with a hydrogen ion ( H+ ) that converts it into NADPH

what is the formula for photosynthesis?

6COꜜ2 + 6Hꜜ2 O + Sunlight --> Cꜜ6 Hꜜ12 Oꜜ6 + 6Oꜜ2

what are the different types of reactions in photosynthesis?

light-dependent reactions and light-independent reactions

light-dependent reactions

a process of photosynthesis that requires direct involvement of light and pigments, taking place in the thylakoid membranes and uses energy from sunlight to add a third phosphate to ADP to make ATP

what reaction can also take low-energy electrons from water and use solar energy to raise them to a higher level?

light-dependent reactions of photosynthesis

light-independent reactions

a process of photosynthesis that takes ATP and NADPH from light-dependent reactions and uses them to build high-energy sugars from carbon dioxide, taking place outside the thylakoids and in the stroma of the chloroplast

calorie

unit of energy; the amount of energy needed to raise temperature 1 gram of water 1 degree C

Calorie

a kilocalorie, 1000 calories. capital C

cellular respiration

the process of energy conversion that releases energy from food in the presence of oxygen

what is the formula for cellular respiration?

6Oꜜ2 + Cꜜ6 Hꜜ12 Oꜜ6 --> 6COꜜ2 + 6Hꜜ2 O + Energy

stages of cellular respiration

glycolysis, krebs cycle, electron transport chain

glycolysis

"sugar-breaking", the process in which the bonds in glucose are broken are rearranged to release small amounts of energy by capturing 10% of the energy in glucose to produce ATP

krebs cycle (citric acid cycle)

second stage of cellular respiration, in which pyruvic acid is broken down into carbon dioxide in a series of energy-extracting reactions