BIOLOGY MIDTERM

organnelles

organnelles

tiny cell structures that carry out functions within a cell

major parts of cell

nucleus, cytoplasm, cell membrane

cell membrane

A cell structure that controls which substances can enter or leave the cell.

structure of cell membrane

fluid mosaic model

major function of cell

protection, transportation, communication

phospholipid bilayer

a two-layered arrangement of phosphate and lipid molecules that form a cell membrane, the hydrophobic lipid ends facing inward and the hydrophilic phosphate ends facing outward.

glycerol head

hydrophilic

fatty acid tail

hydrophobic

can move laterally to allow small molecules (o2, co2, h2o)

function of phospholipid

role of Cholesterol in phospholipid bilayer

decreases fluidity in plasma membrane, which makes the membrane more stable

carbohydrates

enabling cell to distinguish one type of cell from anaother

membrane proteins

integral and peripheral

peripheral proteins

The proteins of a membrane that are not embedded in the lipid bilayer; they are appendages loosely bound to the surface of the membrane.

integral proteins

embedded in the lipid bilayer

function of integral proteins

channel proteins

channel proteins

help cells import or export needed materials

phospholipid

kapag maliit ang dadaan

channel proteins

kapag malaki ang dadaan

transport proteins

help materials cross the membrane

cell recognition proteins

enables cells to distinguish own cells from that of other organism

enzymatic proteins

participate in metabolic reactions such as degradative and synthetic reactions

cytoskeleton proteins

act as muscle and skeleton to maintain cell shape and motility

junction proteins

assist cell-to-cell adhesion and communication

receptor proteins

facilitate exchange pf signals with other cells by changing shape to allow a specific molecule to bind to it

cell wall

responsible for maintaning the shape of cell

located outside the cell/ protection of plant cell

cell wall

plant composition

cellulose

bacteria composition

peptidoglycan

fungi

chitin

cytosol

the fluid consisting mainly of water

cytoplasm

fills the space between the cell membrane and the nucleus

many chemical reactions took place in the

cytoplasm

cytoplasmic streaming (cyclosis)

circular movement of cytoplasm within a cell

nucleus

storehouse of genetic information in the form of dna inside the cells

control center of the cell

nucleus

chromosome fixed number

46

nuclear envelope

special membrane that encloses the dna

nuclear pore

allows large molecules to pass between the nucleus and cytoplasm

nucleolus

dense region where ribosomes, essential for making proteins are assembled

nucleoplasm

cytoplasm inside the nucleus

chromatin

part of chromosome from a non dividing cell

organelles

subcellular structures

ribosomes

site of protein synthesis

formed in the nucleolus

ribosomes

can be attached or free floating in cytoplasm

ribosomes

Endoplasmic Reticulum

interconnected network of thin folded membranes

arrange like a maze, lumen, sites

Endoplasmic Reticulum

this composition is similar to the cell membrane

Endoplasmic Reticulum

rough er

with ribosomes/ hels in the synthesis of proteins

soft er

without ribososmes/ helps in the synthesis of lipids

Golgi apparatus

discovered by camilo golgi

layered stacks of membrane enclosed spaces

Golgi apparatus

the shipping and receiving center of the cell

Golgi apparatus

functions for modification of proteins

Golgi apparatus

cis face

receiving side of golgi apparatus

trans face

shipping side of golgi apparatus

lysosomes

formed by golgi apparatus

round shaped membrane bound structures containing chemcals that can break down materials in the cell

lysosomes

suicide bag of the cell

lysosomes

numerous in animal cells than in plant cells

lysosomes

lysozyme

contain powerful enzyme lysozome, which can defend a cell

phagocytosis

lysosome digesting food

autophagy

lysosomes break down damaged organelles

vesicles

interconnects other membranes by transport of materials

generally short lived and are formed and recycled as needed by the cell

vesicles

3 functions of vesicles

transport, storage, secretory

endomembrane system

nuclear envelope, endoplasmic reticulum, vesicles, golgi apparatus, lysosomes, cell membrane.

vacuoles in plant cells

fluid filled sac for the storage of materials needed by the cell that includes water, food, molecules, iorganic ions and enzymes

plant vacuole

central vacuole

animal vacuole

food vacuole

protist vacuole

contractile vacuole

Peroxisomes

small vesicles around the cell

contain enzymes that remove hydrogen atoms from arious substrates and transfer them to oxygen, thus producing hydrogen peroxide

Peroxisomes

Mitochondrion (Mitochondria)

Powerhouse of the cell

bean shaped and have two membranes

Mitochondrion (Mitochondria)

generate cellular energy (adenosine triphosphate)

Mitochondrion (Mitochondria)

site for cellular respiration

Mitochondrion (Mitochondria)

has its own dna

Mitochondrion (Mitochondria)

Mitochondrial DNA

inherited from mother

from cytoplasm of egg cell during fertilization

mitochondrial dna

Lucy (Australopithecus afarensis)

oldest ancestor of mankind

matrix

where cellular respiration takes place

atp synthase

formed in the form of mitochondria

cristae junctions

fold inner membrane which increases surface

chloroplast

found only in producers (organism containing chlorophyll)

use energy from sunlight to make own food

chloroplast

has its own dna

chloroplast

Chloroplast

outer membrane, inner membrane

chlrophyll

pigment

thylakoid

saclike photosynthetic membranes found in chloroplasts

endosymbiont theory

explains that eukaryotic cells may have evolved from prokaryotic cells

centrosome

small dense region of cytoplasm where microtubules are organized ans assembled

it participates in cellular division in animal cells

centrosome

cilia and flagella

two locomotory projections in eukaryotes

cilia

look like little hairs

flagella

look like a whip or tail

pro

before

eu

true

karyon

nucleus

prokaryotic cells

small and simple, unicellular, nucleus is absent